If it’s of any help, I have similar bass issue with my Proac response 2.5’s in a similar kind of room layout. I have them about 20” from wall which is certainly not optimal. I have bass traps which help a little but on some tracks the bass is bloated. How did I more or less fix it? An inexpensive Schiit Loki tone control. I have not heard the d48 but the issue and context sounds similar. I suspect a speaker like Larsen which are made for very compromised positioning and close to wall placement, might be an alternative choice. I haven’t heard the Larsen’s. (Went to audition them in NYC once and the dealer was so shockingly rude I never got to hear them, another story!).. in most respects Proacs when driven with good power are sublime speakers.
good luck.
good luck.