Interesting question. In general, there’s no prohibition against attending other Districts’ Roundtables, and in fact, that’s a great way to meet more scouters and hear about more ideas from a wider variety of units. And for anyone who is or is considering serving as a RT Commissioner, you definitely need to do this.
That said, I’m not sure I would personally agree that attending 4 RTs (virtual or not) in one month meets the spirit of the requirement. Seems kinda like gaming the system.
However, the actual spirit of the requirement seems to say that you should participate in 3-5 hours of training beyond DL basics, which can be satisfied with one UoS/Powwow (which are generally at least a half-day) or 4 RTs (which are generally 60-90 minutes each).
But I guess this really depends on how persnickety your District Training Chair is, and what they’ll accept. Personally, I feel if you’re making the effort to learn how to be a better DL, it should count.