How can a reaction utilize two or more "Any" molecules

[jlaw9]

If a reaction rule uses "Any" twice, Pickaxe will just use the same "Any" starting molecule twice (writing reaction rules). There are many reactions where two different starting molecules with R groups would be mixed together, but there doesn't appear to be a way to do that with Pickaxe currently. For example, this rule from Metacyc and example reaction:
[#6:1]=[#8:2].[#6:3]=[#8:4]>>[#6:1]=[#6:3].[#8:2]=[#8:4]

Is there a way to use a reaction like this on two different "Any" starting molecules? Would I just need to define one of the "Any" molecules as a coreactant for each combination of two "Any" molecules for which I want to apply this reaction?