Okay...let's talk about party switching. There's a couple of things I've noticed:
1) The lines spoken at trigger points are entirely based on the position, from 2-4, in the party. Since MC never speaks, his position doesn't matter and I'll always leave him in party position 1. This means, for example, if Robot speaks at a trigger point and he is in party position #2, replaying this point with Urnie in position #2 would cause Urnie's lines to be shown instead. There are a few exceptions in Chimoy, in which Poyon eats too much drugged food and, despite being in position 2, ends up switching into position 4 at night (after all, you can't speak if you're drugged & asleep...this is automatic, by the way, and also happens in the original Japanese game).
2) As far as I can tell, ALL of the trigger points are set to trigger party lines when you first get there, meaning that subsequent visits to that location will NOT trigger party lines again. This means that the use of save states for this task is necessary.
I counted around 13 total points in the game where your party members have lines and can be switched out prior to the lines. There may be a few more/a few less points, but I won't know exactly until I've spent a little more time going through the game and checking for them.
So, save states. I understand their use can cause problems in this game and is frowned upon, but, short of getting 210 different people to play the game with a different party permutation, I don't think it's possible to do this without save states. Why did I say 210? Because that's how many permutations are available in Chimoy Town, the first point I decided to tackle with party switching. It took me about two days, using save states, to check all the permutations. Without the use of save states, this would become a daunting task, as the nearest save point may be far away from the point where your party needs to be. Also, from what I've seen so far, save states haven't really caused any problems that weren't there to begin with (for example, Dr. Spanner's garbled line in the ending sequence, which happens with and without the use of save states). I'm not advocating the use of save states, mind you, just making a point that they're necessary if party switching is to take place.
Also, since I've been through the game twice, I've enabled cheats, as well. Specifically, the "Walk through walls" code. This cheat alone probably shaved HOURS off the time it took me to cycle through all permutations in Chimoy, as I didn't have to walk around the buildings to reach the inn.
Using this cheat and save states, I found a couple of issues which might otherwise not have been found. I've uploaded my findings in a...mini-report, I guess, which can be downloaded here:
Report 13:
https://www.mediafire.com/file/7re54v17 ... +-+Chimoy+[F8C3045E].zip/file
Should I continue with the next point in the game with this party switching? I ask, just in case D-D does not like the use of save states & cheats, for this task. I suppose there's always the possibility that you might check my latest report and determine that it's wrong, and everything I noted there actually works fine (that would truly surprise me, but it's not impossible). Obviously, the incorrect flagging of issues (if they actually work fine) would be a great waste of time for D-D, so maybe I should wait until after you've checked report 13 before resuming this party switching project. For now, I'll see if I can get an exact count of points in the game where party switching can take place.