Samsung Messages - receiving RCS messages, but not RCS media across T-Mobile devices

I have an S24+ and my brother has an A54 - we are both on T-Mobile and both on the same plan. I only very recently got the S24+ and I came from a Pixel 7 Pro, where I was using the default Google Messages app. My brother seems to prefer the Samsung Messages app and has been using it primarily. With my Pixel, RCS communication between us has been fine, both in terms of text messages as well as multimedia. After getting the S24, I initially tried using Samsung Messages, as I prefer the aesthetic and cohesion of the app with all the other Samsung native apps, which I've generally quickly grown to like.

My issue is this: It does seem like RCS text chats come through just fine between the two of us (the message details will say "Chat" as opposed to "Text Message"), but I've noticed that a lot of images that he tried to send me through RCS come through as an empty "Cancelled" image. Sometimes his images do come through, but only because it seems to randomly fallback to sending those as an MMS (and not RCS). I also determined that if I change my default messenger app on the S24+ to Google, then the RCS images come through just fine.

I would prefer using Samsung's messages app overall, although I'm also aware that even Samsung themselves are trying to discourage people from using it in favor of Google's. I'm also aware that there seems to be a bit of a discontinuity between RCS servers originally maintained by T-Mobile, and those that Google/Jibe maintain. I checked my settings in Google Messages and it says I'm using services maintined by "my carrier", although by turning on debugging information, I find it's actually rcs-acs-tmo-us.jibe.google.com.

Is there any possible solution to ensure RCS chats *and* multimedia messages (not necessarily MMS's) come through just fine on the Samsung messages app? Or should I just grin and accept the fact that Samsung's messages app is basically deprecated, and that I really ought to use Google? Because as much as I prefer the cohesion of Samsung's app with the rest of OneUI, I feel the broken functionality is a deal-breaker, and I'm reasonably confident the answer is gonna be "just use Google Messages".