Co-loading with Stand is really simple: In general, you just inject your other menu(s) of choice first, and then use the Launchpad to inject Stand.
|Menu||Stand Version||Load Order|
|Impulse VIP 1.2.6||0.41.2||Stand last|
|Phantom-X 6.9.1||0.43.2||Stand last|
|2Take1Menu 2.23.0||0.41.2||Doesn't matter|
|Ozark V9||0.35.4||Stand last|
|Cherax 4.4.3||0.40.14||Stand last|
|Disturbed 188.8.131.52 beta||0.36.4||Stand last|
|X-Force 5.6.6||0.41||Stand last|
|Kitsune v3.1.2||0.37||Stand last|
|Hextic 2.9||0.40.14||Stand last|
You won't have any issues co-loading external menus, like Kiddion's Modest.
There is no consensus among mod menu developers on how to deal with other mod menus, and some even seem to ignore/deny the existence of others. As a result of that, most mod menus won't even load if injected after another one. Stand will try its best to mod an already-modded game, but there still is a handful of features that might not work in Stand, and you should use the first menu for, instead:
If you want to unload menus in a co-loading setup, you should unload them in reverse loading order, e.g. if you loaded Stand last, it should be unloaded first, otherwise you risk breaking other menus.