I remember early on in FFXIV when RMT spam was a huge problem, the community was asking for a right-click blacklist option from the chat window. At the time, the moderation team on the forums had the same excuse- what if someone blacklists someone by mistake? This was actually implemented later on in a patch, and it works very well... not sure why there were any concerns about accidents. So my point is, this is kind of the same situation... someone might accept the D2.... by mistake? How is that even a concern based on the CURRENT option, of getting a D2 like it or not.

Another slightly less cumbersome option for the devs would be to change the blockaid command so it blocks spells by everyone, even those in your party/alliance now that HNM camping isn't a thing anymore.