This animal shelter has removed all interior doors and asked me to hang these new plastic screen doors. Normally I would chisel out a space in the door for the hinge, but this is plastic not wood. I don't have a router so I'm wondering if there is an alternative? Maybe go back and deepen the mortise - - chisel out more space in the door jam to make room for the whole hinge. The door would be a tight fit without removing 1/8th" from somewhere. Maybe I'm making this more complicated than it should be, but once I cut there's no going back, so I thought I'd do a sanity check before chiseling.
You could try chiseling out the wood door frame to accept the space. I have no experience trying to mortise a plastic door so just guessing. I would definitely try it with one and see if it works before moving on with the others.
Awhile ago I was working for a guy who had a hack brother in law hang all his new solid core interior doors. The guy didn't do the hinge gains, just screwed the hinge to the door, needless to say the doors were far from smoothly operating.
Another alternative would be to tell the animal shelter to obtain proper doors to hang in the existing frames, if they want to keep the existing frames.