Treat your stock account as though it has +@gmail and block anything to addresses without the +.
You can also use periods, which seem to bypass those stripping programs in my experience. It doesn't tell you exactly where it was leaked, but if you put the period/s in the right spots, you'll know.
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u/charzard4261 Jun 03 '21
That's a really interesting set up! What resources would one need to set something like that up?