prozone
Let's say I want to just record some short midi sequence, edit few changes and copy/paste it in same track.
But even if I just simple quantize it I can't copy/paste whole sequence properly, because what I copy are notes with that pre-quantize time space on beginning of clip so I can't paste it on specific place.
Ah. I see. So you want the clip to be able to "Snap" to the Timeline after your edits (and I'm assuming you want the first note after your quantizing/editing to be the Snap point... like it should appear right at the 1 beat of the measure it is being pasted into).
In that case applying trimming (as Brundle said) or manually snipping/slip editing the clips or bouncing or whatever just to get the clip trimmed seems like what you're gonna have to do (despite your desire to not have to).
I agree that having clips shrink as data is removed is more annoying than having to trim clips.
Maybe some of the smarter guys know a setting that will do what you want.
Cheers.