I've combined various GABAergics including Amanita with my Harmalas/Rue, it's fine and there's no negative interactions there. The GABAergic effects are actually helpful/beneficial especially for cleaning up the Rue's bodyload because it can counteract the GABA-A inverse agonism of Harmaline. As for Amanita itself though, i've never really gotten much out of it, i mean it worked and i felt the Muscimol and Muscimol is nice, but i mean, it's a GABAergic, feels like other GABAergics to me. With that said though i have noticed some slight psychoactive effects from Muscimol's GABAergic properties, but i'd really need to work with Amanita more to really see what it may be able to do, because as it stands currently there's not really much of anything to Muscimol that attracts me to it. As far as Amanita with Rue though, the combination worked pretty much the same as when i've added Lemon Balm or benzos or Alcohol to the Rue, it cleans up the Rue's bodyload, provides some GABAergic properties, so it's definitely a doable mix but as far as there being anything special going on with Amanita, the jury is still out for me, but like i said i'd have to work with it more to really see what all it may do.
Just make sure you're properly decarboxylating the Amanitas though, so that the Ibotenic Acid converts to Muscimol, then there shouldn't be any nausea/vomiting, at least i haven't experienced nausea/vomiting from them and from what i've read it's the Ibotenic Acid that causes the side-effects, so make sure the mushrooms are properly dried and/or you make a tea from them and give em' a good boil. I've straight up eaten the mushrooms themselves, and i've made them into a tea, i think i prefer the tea but neither of them made me nauseous.