Wow, when you decide to do something you do it! Correct decision on getting the speakers back in use, way too lovely to have on the sidelines, being inactive.
Maybe look at getting some desk stands for them. I got some isoAcoustic 155s for my AE1s, much improvement from the isolation foam pads, and much much better than having them flat one desk.
This next is not a serious suggestion to the original topic: since you like Quad, you have the 11Ls, and were looking at their headphones, have you seen the Quad 3? It's an all in one DAC, Headphone Amp, Speaker Amp, USB-B input. Since the later USB-C contains the specifications from the earlier USB-A+B, you can get a cable to go between C (computer side) to B (DAC side). There''s 2 issues: it's not cheap. it's also retro in it's EQ functionality, as in it's only got 2 dials, bass and tilt. Buuuuut all Quad setup... lol
Please don;t take that as a serious suggestion, not seen any reviews of the Quad 3 yet.