I'm also a TRPG player and GM, and I have total aphantasia. I can't possibly speak for all aphantasics, but I wouldn't want you to make most of those accommodations for me if I were a player at your table.
Metaphors and analogies are very useful for me, because they provide archetypes of mental models for my understanding of the world (in this case fictional). There's nothing inherently visual in them or difficult for me.
I love to see artwork, and maps certainly help understand the geography of a scene, but I'm not sure that has much to do with aphantasia. If the GM's verbal description is good, I actually prefer not seeing pictures, so that I can fill in what I can with my own imagination.
Maybe the biggest thing that aphantasia does in this context is give me a strong filter against "useless" details. If you describe a monster with knife-like jaws, or a woman with pink bubblegum hair, that's interesting because they are potentially useful "action hooks", i.e. knowing those might influence my decisions, be it tactics or conversation prompts. On the other hand, if you describe all the random colored spots on the monster's back or tell me that the woman's hair is blond with curls "like overcooked macaroni" or whatever, those are not going to mean anything to me, and they're going to bore me.