My large plants I want to try crossing with are a very mixed bag. Big Hill is a determinate bi color with larger then normal flowers. Fuzzy Wuzzy is a fuzzy bi color dwarf. Cherokee Tiger Black is a dwarf with chartreuse foliage and purple striped tomatoes. Lucinda is a carrot leaf determinate with green on green striped tomatoes with tangy flavor similar to its Green Zebra parent. No white genes this year since Melon Ball didn't come up

Big Hill would need to be a micro x Big Hill if I want to check for crosses in the F1 HOWEVER the other three varieties have recessive foliage types. This means I can make my crosses either way and still be able to recognize successful crosses in the F1 plants I grow out. Fancy foliage x micro dwarfs will all have regular leaf in the F1. And of course micro dwarf x fancy foliage will grow to dwarf or larger size. While it sounds like I am after foliage genes in this years crosses I am collecting color genes and hopefully some flavor genes.
I do promiscuous tomatoes in the summer here, very interested to see how big hill does for you. Did any of your crosses take?