Unfortunately, it's still not clear. Bruce at xJet contacted the FAA directly and asked whether a certain BnF model needed to be fitted with RemoteID. They answered by pointing to their ambiguous rules. It's likely that anything that is a complete "system" meaning Tx and Rx are included will require Standard Remote ID that broadcasts the position of the craft AND the pilot. That's why DJI requires you to use your phone with their system because the Tx doesn't natively have GPS, so they pull the coordinates off the phone plugged into the TX.My understanding that nothing except for fully RTF RC aircraft will require Standard RID. Ergo, all PnP.and BnF offerings, in addition to anything you build, will be able to use an RID module. Horizon has already done some repackaging of certain products to fit this approach. Items previously considered a RTF package will have the battery and charger removed, or some other mod so that not everything you need is in one box.
If the quad you speak of was not 100% complete and RTF, they are legal. Also, if fully RTF and manufactured before the cutoff date last year, that production model is exempt from Standard RID and can be sold until that stock runs out. You would need to add an RID module later this year.
For BNF, ARF, etc. it's not clear (but implied?) that these must come with Broadcast Remote ID that advertises the location of the craft only. Again, the FAA couldn't be bothered to clarify any of these questions which shows their complete lack of understanding of the hobby and the industry.
As this rolls out I foresee mass non-compliance with any of this garbage. I do applaud the FTCA and FPVFC for fighting through the system to claw back to some semblance of reality, but the reality is that folks will take the path of least resistance.