I don’t know know of any formal campaigns involving amateurs though the AAVSO did contact the author offering support and there are a number of observers contributing brightness measurements. Here is the thread on the AAVSO forum
https://www.aavso.org/sdssj14302303nsv6690-smbh-binary-collision-candidate
I took a couple more spectra and contacted the author who though they might be showing some changes and would follow it up with some measurements of their own, though I have not heard anything since. A quick look at the AAVSO light curve does not show anything obvious.
Cheers
Robin