what’s most important is the quality of the DSP unit itself, not whether it adds an additional A/D conversion step at the input side.
I (largely) agree with you on this subject. I’ve auditioned high-end active setups and found that they sounded wonderful.
A conundrum and bottleneck of sorts is the DSP unit. As you pointed out, quality is important. Relatively few choices exist, and most come from the pro world (which I don’t consider a disqualifier in and of itself; indeed, folks who do audio for a living have long since solved problems that leave seasoned Audiophiles drowning in a glass of water - especially in the digital realm. But I digress).
A DSP / crossover unit does add an AD/DA conversion, usually whether it’s needed or not. In fairness, the benefits of DSP largely outweigh whatever sound degradation may happen as a result of that conversion.
A DSP unit needs to have the appropriate IO combination for your project. For instance, a dbx venu360, which is a 3x6 unit, works well controlling a pair of 3-way speakers, but has no additional outputs in case you wish to add subs later.
Also, most DSP units support rates up to 24/96 or 48/96, so if DSD is your thing the DSP unit will convert and resample it.
Notwithstanding the above, active / DSP speakers sound wonderful. I would definitely recommend anyone serious about gear audition them.