Not to muddy the waters here, but a lot of the 3D magic you heard with the SET amp and RM7si speakers was probably not in small part due to the excellent imaging/soundstage capabilities of the speakers as it’s just a core strength of the brand (although I’m sure the amp contributed as well). Another option would be to try these RM22XLs and see if they recapture a good portion of that magic with your existing amp, and if not you can likely turn around and sell them for little/no loss. Just another option to ponder FWIW.
https://www.usaudiomart.com/details/650003701-joseph-audio-speakers-rm22xl/