I recently read that devs officially added Blood Infusion, Cursed Blood infusion, Oil infusion and Cursed Oil Infusion to be used for summoner Incarnate.
There is no mention on the Divinity 2 pedia about these skills and i was unable to find a detailed patch history from 2019 for Divinity 2 to check has it been officially listed anywhere.
I tested it myself (only had minor mods and larian gift bags enabled like Crafter Kit and Pet Power) so its definitely a part of the official game:
Blood Infusion (summoner book + necro book)
Cursed Blood Infusion (source summoner book + necro book OR summoner book + source necro book)
Oil Infusion (summoner book + geo book + oil barrel)
Cursed Oil Infusion (summoner source book + geo book + oil barrel OR summoner book + source geo book + oil barrel OR source summoner + source geo + oil barrel).
KEEP IN MIND NOT ALL SKILL BOOKS ARE VALID FOR THESE RECIPES!
For example i could not make any of these using the Inner Demon source summoner book.
Try with several different books from the adequate spell schools - it will work.
Enjoy your new Incarnates