Well, not the only way. You can always go into edit mode to the envelope page and record the edit into the track using our old friend Transmit Edit; record that edit into the beginning of the track (or wherever you want the delay change to start), and that's that. I think it's only going to be a single sysex message, so there will be no latency problem.

Really, this is a pretty simple procedure. Check the archives for past posts on how to use the Transmit Edit function.

As for Purple Spin, check the archives on how to set up your EFX in perf mode. I think I did a pretty detailed one a while back about setting up a certain perf part to always use the patch's Patch-Mode EFX settings except for rev/chor, which you can set manually to come close to the original patch's settings. This, too, is a pretty simple procedure, but you'll have to search the archives to find the posts.

In general, almost any patch that uses insert EFX in Patch Mode will sound different unless you set up a perf part to import Patch-Mode insert EFX and then set the rev/chor as close as you can to the Patch-Mode settings.

But it certainly can be done. Don't give up.

Good luck.