When answering this question, I decided that I wanted to test the second part in a Replay on Showdown. However, I realized that only some formats allow for Dynamazing, which was required for what I was testing. I remebered that VGC 2020 would work, but what other formats allow the user to Dynamax/Gigantamax their Pokémon? Other than answering questions, I feel like this could be useful for those who want to battle in a format where the mechanic is legal, but aren't sure where it is.
Thanks in Advance!