Is there any type of clean up take layers feature in either X3 or Platinum to automatically remove layers that no longer overlap after editing?

The is a feature that deletes empty layers.  Sorry, but I'm not sure of what you are trying to do.
 

Automatically remove unused take lanes when audio clips are not overlapping.
Place the non-overlapping clips onto a single take lane.
 

Bounce to Clip(s) with selected lanes will consolidate clips into the highest numbered lane of those selected. Then right-click the comp clip in the parent track and choose Remove Empty Take Lanes.

Sonar doesn't automatically do this because it considers each recording a separate take. Moving a clip from take 3 to a lane on take 5 would destroy this paradigm. As Brundlefly said, you can bounce to clips manually, then delete lanes.

If you know beforehand that you're going to track bits separately it can also be helpful to put them on separate tracks altogether.

Now I remember what the OP is talking about. Sonar used to be able to reorganize the take layers. I think the new paradigm has replaced that. It is a little less automatic but it's less likely to give you results that is hard to follow.

Thanks all.
I sometimes bounce clips & remove lanes at the end of editing a track or finishing up project but I'm looking to consolidate lanes the way I described.
I'll assume it's not possible in either version.

Nope. One of the main differences between take lanes and layers.

Maybe this will help (my REVISED 2-12-15) notes on How To)
 
Comping

• Widen the track (top to bottom) enough to get to clear space below the Audio icon on the left side of the track
• Set up a loop.  Right click record, and select Comping.
• Hit R and record over and over and over, until you think you have a few good takes, or pieces of takes you can stitch together to make a good take.  Stopping (spacebar) and re-starting record (R) is OK.
• Click the track’s Expand/collapse Take Lanes                         button to show Take Lanes. 
• The Last Take will be a Partial Take that is caused by the time it takes you to get your hands off the guitar (or stop singing) and hit the space bar.  This last partial clip will cause all the clips to get split, and generally cause a mess.  To handle the little takes that get splattered about: click on that Partial Take and delete by hitting the Delete Key (this Partial Take is usually in the top lane).   Zoom out enough so you can see the entire take, end to end, and then swipe through the entire next take down from where the Partial Take was (starting outside the clip) with the Comp tool  (it is under the Edit button) to "heal" the splits caused by the Partial Take all at once
• To cut all the takes into phrases (if you want to stitch a new take together from pieces of several takes), drag the comp tool over the phrases to be isolated.  Each phrase in EVERY LANE will get separated by a Cut where you started to drag, and where you stopped dragging ... on whatever lane you are dragging over.  (If you screw up, “heal” all the takes as in step above, or use the Smart Tool  to drag-move split points that start/end just slightly in the wrong place.)
• Hit Play and Click the takes (or phrases within takes) with the smart tool  or comp tool  to audition. OR Try Speed Comping (Shift+Spacebar to loop the first segment, then arrow up/down/right/left to audition different takes/segments, and Enter to make a clip active.
• Once you have compiled the performance you want, Right-click the Comp clip and select Flatten Comp on the pop-up menu.  This will create a“Comp Lane”just below the actual track. Now you have a Perfect Performance!
• HOUSEKEEPING:  If there are multiple comp-areas in one track (i.e., multiple loops you set up in one track), there will be multiple comp-lanes.  Comp lanes below the top Comp lane will auto-mute and otherwise cause problems.  To avoid this, you will need to drag the contents of all the Comp lanes in the track into the top Comp lane.  HOWEVER, YOU MUST FIRST (!)  identify the EXACT start location [e.g., 14:03:237] of the clip in the comp-lane you intend to move by clicking on the clip and then clipping on the “set loops to selection” button and WRITING DOWN the start time.  After you drag it to the top comp lane, verify that the start time is the SAME; if not, use the Slide process to move the clip the required number of ticks.
• You MUST NOT (!) delete the top Comp lane (where you just dragged all the Comps in the step above). 
• Zoom out so you can view the entire track, beginning to end.  Delete the lower lanes by clicking the little X on the left end of the lane.  As you delete you DO NOT want to see any of the track data disappear (Ctrl-Z undo!) (this is why you zoomed out, to SEE what is happening).
• Remove the Clip Lock. Click the Clips pulldown and Bounce to Clip.  This clip is now a clip like every other clip.
• Click the track’s Expand/collapse Take Lanes button to hide all the Comp and Take Lanes. 

A few extra tips you and others might find helpful:
 

GregGraves

• To cut all the takes into phrases (if you want to stitch a new take together from pieces of several takes), drag the comp tool over the phrases to be isolated.  Each phrase in EVERY LANE will get separated by a Cut where you started to drag, and where you stopped dragging ... on whatever lane you are dragging over.  (If you screw up, “heal” all the takes as in step above.)

Other options to correct screw-ups:
 
     - Drag-move split points that start/end just slightly in the wrong place.
     - Ctrl+Z or go to Edit > History to step back only as far as necessary.
     - Select two or more adjacent clips, and Ctrl-click with the Comp tool to heal them.

• Hit Play and Click the takes (or phrases within takes) with the smart tool  or comp tool  to audition.

Try Speed Comping (Shift+Spacebar to loop the first segment, then arrow up/down/right/left to audition different takes/segments, and Enter to make a clip active.

• HOUSEKEEPING:  If there are multiple comp-areas in one track (i.e., multiple loops you set up in one track), there will be multiple comp-lanes.  Drag the contents of all the “Comp” lanes in the track to the top Comp lane.  Comp lanes below the top Comp lane will auto-mute and otherwise cause problems.

Try housekeeping before beginning comping/flattening. Select all the clips in a later comping section and Shift+drag them to occupy the lower lanes (assuming they don't overlap an earlier comping section). Then Remove Empty Take Lanes.

• Click the track’s Expand/collapse Take Lanes button to hide all the Comp and Take Lanes.

Shift+T to toggle take lanes when the button's not showing.