If a load of people needed it then I'd be more likely to consider implementing it (even against my personal feelings on the matter) but so far you're the second person to ask about it in the past 3 or so years since the WACUP streaming support was introduced & it's not just a few hours work to get it implemented.
The SCv2 artwork support was never a finished feature so it having issues when used is expected & gets worse the larger the artwork that you're trying to send. It's not helped that the appropriate changes needed to resolve the hiccups weren't made (due to lack of dev time) that occur on song change due to how the artwork sending from the SC DSP effectively kills the audio stream output until that completes.
From what I remember, the solution would have been to have the artwork sending also allow for sending through some of the audio instead of just a solid stream of artwork frames which would have helped minimise the playback hiccup.
However, the best solution would have been to change the DNAS itself (not likely to happen & it's then whether I want to even implement v2 streaming support into WACUP's streaming server) & how it requires the artwork to be provided so it's not able to block the audio stream (ironically the v2 protocol is a bit more like how HTTP/2 works vs HTTP/1 but didn't take full advantage of the ability to multiplex different types of stream data).
-dro