Hey man, I assume that you’re talking about changing patterns via program change and I wonder if the lag you experienced is a result of the “one bar late” behavior? Have a quick look through this topic and see if it’s the same thing, because there are a few proposed work arounds given.
I understand it may not be the same for you, but if you haven’t already investigated this, it’s the first thing that comes to mind when I read your post.
You may need to try P locking a program change to a step and then microtiming it to before the step to make the change occur when desired rather than setting the track information to perform the switch, but I’m still not sure that it will solve your problem.
If I can help out I will, but it might just be the elektron as slave device PC behavior which you’re up against, in which case nobody but elektron can really change it.
I assume you already read how the PC numbers correspond to bank and slot and that your problem came after trying to implement those specific changes to patterns other than the default of following same bank / same pattern.
There are more topics about the same thing if you search the term “one bar late” but the one that I linked is the main one with most of the collected knowledge.
Good luck and let me know if I can do something else to help you out!