A) My users may not know how to use Amethyst
B) I also may not know how to use Amethyst
Funny enough, before realizing these things, I had already (recently) drafted a feature request for Amethyst to expand upon its relay management options. I talked a bit with Vitor about this and overall I can see how this is difficult to approach for any client dev. You can view that here:
https://github.com/vitorpamplona/amethyst/issues/1251
In any case, I am looking to pioneer forward with basically a re-design of NoteDeck using bun.sh (for browser) and/or buntralino (for standalone) to hopefully encourage people to work on the same client together. Queue the xkcd competing standards meme.

The reason I'm somewhere between "a nostr client" and "LogSeq" is because my first priority is explicitly relay management. Jumble.social seems to have nailed this, so I will probably be getting comfortable with it this week,. So far I am only interfacing with this relay using Jumble. I don't think I can remove posts, so please note that some boosts in Amethyst may be coming through on these relays.
Back to Amethyst. I don't know how anyone else is using it, but I'm completely embarrassed to admit that I did not fully grasp the control schema. It seems simple at first, then complicated, and back and forth.. But overall it is designed to be useful. I'll break it down just in case anyone is struggling with it still, and I may go on to republish this later for others:
R/W matters. If you choose to write to a relay, it is going to be enabled as a default option when you go to post any note. If you choose not to read from the relay, obviously you will not see the notes that are only posted there. To sum this up, you should probably disable "write" on all of your 'general relays'. This means you will no longer blast the network with each post, but also means you will still have to select each relay you wish to publish to (at time of posting).
The secondary issue that arises from this is that boosting content will no longer "blast" to a bunch of relays. You will need to quote or fork a note to proliferate it across other relays. The only things that WILL work- is dm's and draft. This is the apparent "bug" with Amethyst's relay pooling. There is not a specified way for the app to discern a difference otherwise, except what the user has laid out in their configuration.
Lastly, I don't use the other features of Amethyst myself. I'm a kind-1 maxi for now, until a client can prove to offer a better experience. Otherwise I try to use dm's sometimes, but that's pretty rough lately. So, I disable a lot of the other elements under general relays, leaving only one or two in global, and most have home enabled.
Where we're left with is Amethyst provides the best mobile experience, but can be a real bitch to isolate a relay on, because of how it toes the line with its functionality. Relays can easily clutter up with boosted content and become a nuisance within our home feeds. This is sub-optimal, so I'll just say, I hope for the best experience for everyone! :)