I don't know if I would call them "boundaries" per sey. My current idea to run by him is by possibly coming up with a "safe word" so to speak. Something he can either text or say to me, that still carries a message of love without directly expressing any feelings on his part if he can't. Maybe even something I can use if needed. This way, my anxiety from past relationship and abandonment issues won't be triggered, and I'll know he still loves me.
We set up a lot of boundaries and agreements before we even got back together- we literally laid everything on the table. So I know he will be open to something similar to this in order to keep our relationship strong and healthy.