You might already have seen requests of it, or had in mind since before, but please add summoning by means of reactions during the upcoming fortress mode work period. This is something modders have wanted for ages, and now that summoning has been added it would be a real shame if it isn’t easily accessible in fortress mode.
I do believe, that even if summoning directly through a reaction isn’t added, modders will find a way to make it happen. But this method will be ridiculously lenghty and overly complex*, and will both make adding summoning reactions a pain and bring a few strange limitations.
I am aware making full support for reaction summoning might be tricky and time consuming (if the framework allowing it isn’t done already), especially since much of it might have to be reworked when the magic comes for real. However, adding an extra reaction token that forces the worker to do a summoning interaction shouldn’t be as difficult, so I suggest doing that, for the sake of dwarf-made golems, dwarf-made homunculi, dwarf-made robots, and dwarf-made demon summoning portals.
*
The method I imagine modders would use:The reaction creates an item, that instantly vaporises into a cloud of syndrome-bearing gas. The syndrome transforms those affected into a certain creature, that naturally knows and uses the summoning interaction. The syndrome then wears off and the worker affected by the syndrome/gas transforms back into a dwarf