Since corner placement is of primary concern, AN-E’s are worth a try. In addition, the signature versions of Audio Note electronics are the sweet spot in the line up. I would take for example a silver signature level 3 over a base version level 4. You dont have to run silver interconnects or speaker cable but you can always upgrade to those later if you want to squeeze out more performance. The E-Spe’s are wired with silver wire but have copper voicecoils so you dont need to go crazy with silver ic’s and speaker cable unless you want to eek out the last 1-2% of performance. In my opinion, the 8wpc from a 300b set is barely enough for the spe he’s depending on your listening preferences. I listen at low levels but like dynamic snap when called upon. YMMV.
I also concur with @jasonbourne52 @stereo5 that you havent heard how good your ARC gear can sound yet. Far from it. Frankly, your 5se preamp is so good you will have to spend $$$$$ to better it within Audio Note. You might even consider hanging on to your 5se if funds allow. Its a special preamp that will be in high demand for many years to come on the preowned market and maintain its value. And good luck finding another one if you change your mind and want it back.
Any of us who have taken a deep dive down the Audio Note rabbit hole will attest that its great gear, it does what it does very well but if you are buying new, it depreciates far more initially than you may think. A big haircut awaits if you want to reverse course. A really cool option for you might be for you to demo a ref80s amp with the audio note E’s. Then you could sell your ref150 and buy the ref80s. The ref80s has a triode mode and I would be very curious how that system would perform with the AN-E’s. If you are demoing the e’s and they don’t quite float your boat, you could reverse course and pick up a pair of Sabrinas...they are a bit more placement agnostic than the Sophias IMO. I have a friend who has Vandersteen Quattros(I dont recall the version naming conventions) with a similar ARC setup and given the adjustable bass on those speakers, he has them very close to the walls/corners with fine results.
Good luck and as always seems to be the case, be careful when your setup is predetermined by domestic/decor priorities. You will have a wide sweetspot with the E’s in your room but that sweetspot won’t be as sweet as you might think. They sound pretty good no matter where you happen to sit but all of that toe in that is required, I repeat required, for the Audio Notes will compromise your presentation in other areas. With the E’s in my systems and rooms, I found myself feeling that they don’t suck musically and are a terrific speaker for a normal domestic setting. Just please don’t slip into the trap that some of us slip into when we think we are going to have dedicated listening room performance in a non-dedicated listening room. That won’t happen.