Manually increasing the repeat list / play count counter

OS: Windows 10 (10.0), Arch.: x86_64, MuseScore version (64-bit): 3.0.2.5315, revision: a8b90a8

So, after a few hours of fiddling with this score, I've learned a ton about how the repeat list / play count stuff for voltas work. But, I can't seem to figure out the last little thing I need to make this score work.

Here's what I'm working on: a transcription of a march where the trio is repeated with a break strain in between the repeated trio. In the original, this is done by skipping ahead after the first ending of the trio to the break strain, DS-ing to the beginning of the trio, and then taking a second ending which is also the end of the piece.

I have spent hours trying to get this roadmap to work and have noticed a couple things that may or may not be true:
1) The repeat list seems to work off of a counter of some sort that is:
a) incremented by an end repeat barline; and,
b) is only reset to 1 by a start repeat barline
2) Del Segnos do not increment this counter, I thought they could be used to reset the counter to 1 by checking "play repeats" but that didn't test out. Maybe it resets it to the count that should be at the place where the segno is?
3) The "Play Count" option in measure properties for a volta are only present if there's an end repeat barline
4) If you do not reset the counter with a start repeat barline, the repeat list number in a subsequent first ending volta will need to match the count of the previous last ending

So, with all this learned...

How can I make the attached score bend to my will? Right now, I think the trio's first ending picks up its repeat list number from the counter position at the end of the second strain since the counter does not seem to reset (since a segno is used to go back instead of a start repeat barline)

I have a way to fake it out for playback using partial measures with hidden barlines and a hidden fine... but what I'd really like to find is a way to get the DS (or some manual mechanism) to increment the repeat list /play count counter.

Easiest way to see the issue is to start playback at measure #42 (second ending of the second strain).