What I have done in the past is have N+1 recipes, where N is the number of variants that I want to make. I create one recipe for creating the extract, then I create the N other recipes for the following stages. Sometimes I play with hops, or specialty grains, or yeast strains.
I've used this approach for as many as 5 different simultaneous variations. I had a single 7.5 gallon mash to produce a standard Pale Ale wort, followed by 5 different boils with different steeping grains in each.