Changing the min/max project tempo envelope display range in the preferences only affects the current project. Other opened projects are not updated with new setting until reopened. This causes all envelope points pasted in those projects to have different BPM values than they should.
Setting the display range using the API with the tempoenvmin/tempoenvmax config vars does not update the active range in any currently opened projects.
Additionally, maybe pasted tempo points should preserve the original BPM values (like manually entered BPM values, which they may be) instead of being clamped to the display min/max setting?