Tempo map is awesome and can be used to realize even the most complex task. I insert and delete measures all the time with very complex tempo maps. I'll describe how to from X1 so it might vary. To insert measures and have the tempo slide over, you must place the now bar where you want to insert time, go to Project, Insert time/measures. Where it says Slide, make sure you tick all boxes (events in tracks, markers, meters,key, tempo changes), click the amount of measures or time, hit ok. You will see the tempo map slide over to make room. 😄 To delete, just highlight the measures or time on the timeline, Edit, Delete, then again Tick all these boxes (events, track bus automation, tempo changes, meter/key changes, Markers, and Delete Hole, shift by measure if it's a whole measure) Then your tempos during that section will be gone too. To keep your tempo curves the same but speed up or slow down every tempo change, use, Process, Fit to Time, Modify By changing tempo map, For faster overall, set the New Thru to an earlier time, for a slower overall, set the New Thru to a later time. For very fine ritards and such, just turn snap off F12, and sometimes you may need to zoom in or out on the tempo map to reach slower or faster speeds. I use the tempo list, say if I've Tempo Mapped a cover song and then want to straighten out their tempo by highlighting all but the first tempo then changing that one to my desired tempo. Sometime I map out 3 tempo maps of three version of a cover and then match pitches and tempos, either a new fresh tempo, or the map from my favorite one. Sometimes I map a tempo map to a cover song and then adjust the whole thing up or down using Fit to time. If I can help, let me know! 😄