Changing sample in phrase without retriggering envelope?

Some chiptune trackers have a macro feature that allows the pitch, amplitude, and/or waveform to be changed. Some examples include HivelyTracker, DefleMask, and Famitracker. I was wonder if I can do that with the phrase editor in Renoise with multiple pulse width samples. The problem is that every time I change the sample, the envelope retriggers. How do I not make the envelope retrigger so I can do wavesequencing on Renoise?

The envelope will indeed be retriggered -

but you could maintain the envelope position (Exx) manually when you program a phrase.

Or you could implement a macro which crossfades between multiple waveforms

(using this trick, you could even automate this from within the phrase itself…)