apologies, not implying its your fault or its an inconvenience.
I’m also really grateful for your help in testing this out, whilst its frustrating for me (as I appear to be going around in circles fixing this), having it crash for someone else is very useful feedback.
as for now…
well, I couldn’t reproduce your issue, but then I cleared my 000 patch, and now I can.
no idea why…
though, shows the power of having multiple users testing, we all having things setup slightly different!
this is leading to me believe its some kind of “random” memory corruption, which explains why the issue seems to move around, and also why you and I see different behaviour.
this is a tough one, as Im not seeing it on my Mac, when testing the trax plugin on its own.
but then again, Synthor is doing its own plugin loading, has its own version of Juce, and its own custom memory allocator - any it could be (likely?) that is one of these things thats somehow not playing nicely.
the issue is, theres no current leads as to where the underlying cause is…
the one piece of ‘good news’ is - you have it crash before loading anything…
this means its not the loading of modules within Trax.
can you do a few tests for me…
preparation - lets get to a ‘known state’
clear the default 000 patch. and save it, the reboot
now when the SSP powers on it , it loads a blank patch.
(you can restore factory patches later if you want them, or use wriN to save the 000 patch)
follow exactly, don’t bring UI of trax up, unless stated 
a) create TRAX , and delete it
Im assuming it will crash
b) create two TRAX ,
delete one - doesn’t crash
delete 2nd - it does
c) create one trax, bring up UI
now delete - does not crash
d) create two trax, bring up UI on
delete both, does not crash?
create trax, no ui
delete does not crash
hopefully, you’ll get the same, which at least shows we are consistent
from the above, its feels like its a variation of the original issue, where deleting plugins without bringing the UI up, causes a crash… but Ive no idea why its now a specific issue just for Trax.
but at least its something to go on…
the UP/DOWN red buttons on the SSP are equivalent to the red buttons next to the screen on the XMX.
so holding up will always bring you to the main mixer screen. (with vu meters)
similarly holding down, always take you to the performance screen.
the main reason for this is when you are in the module view (e.g. CLDS), I need up/down up/down are used to go between parameter pages.
basically, I ran out of buttons/gestures to use on the xmx, as every button is (potentially) used within a module.
I tried various gestures, including two button combos, but I found most either fiddly or difficult to remember.
so I went for one extra gesture HOLD = 2nd function.
also I liked the idea that hold up/down would take you to two important screens mixer/performance - as the idea is once the patch is build, these are the screen you want to ‘perform’ with.
I will say it takes a while to get used to… and ofc, its possible to refine.
in the end I chose one way that was consistent / worked - with the idea, that once I have more users we can discuss the pros/cons of variations to improve.
though, ofc, I want to get it stable first 
what next?
anyway, Im going to try a few different things to see if I can squash the above issue…
though, Im a little worried, I’ll again fix in one place and it’ll pop up elsewhere.
if it does, Im going to have do try to find a better way to test / debug the issue - but that could take a while, so this ‘quick fix’ is worth a try.
Ive also ordered some more sdcards, so I can create a 100% fresh image for ‘final testing’, as its inevitable a box you use for dev is going to end up with some ‘other stuff on it’
e.g. I have dev versions of perfcmd / trax standalone on mine, plus all sorts of other ‘stuff’ I experiment with. none should impact, but you never know !
but that’ll take a day or two to turn up (here in the mountains
)