^^^^^^ that's the part of the request I think. I also do not want Reaper to not allow me to override it, open project with different buffer settings of course. It also can be pretty problematic with more open tabs each requiring different buffer size (as already is with samplerates). I although need that the project carries this essential information (to sound as intended). If I accept it or override for any good reason at that time is just user's informed decision to do that. In actual state I may have synth project made with 128 or even 64 samples buffersize to have all that snappy envelopes and parameter modulations. Then I work on something that makes me to change the buffersize to e.g. 512 samples. When coming back and loading that previous project I want to be informed about the mismatch and not blindly open the project without any info/warning and then be surprised why it sounds like a sh*t, just to remember later that I have 512 instead of 64 samples buffer :( This information is really crucial and BTW there is my another Feature Request that also deals with this problem in some form at least: