@Hammerojustice
Steve,
If you can do it on your phone or a laptop, here's a couple of strategies I have used (unless the kids are banned from using their phones and you can't either):
First night - five minute "bathroom break" - I just ducked out of a gathering. Got my 3 dibs and returned - no one had a clue.
Another time, mid swap, told the friends I was with at supper what I was doing and had a cheering section of two as I snagged my dibs.
The younger set will probably get a kick out of you swapping seeds online. Share the joy.