Will lowe's or home depot rent you a jamb saw? Worth asking.
I looked and the store here has the manual ones in stock, but the cheap kobalt ones they suspiciously don't carry anymore.
I did find a Japanese woodworking saw that MIGHT work in my room stash.
Our home depot has the power tools for cutting sun floor flush to the wall and a vibrating cutter for door jambs.
Rental on the toe kick saw is ok but dang I hate to pay $20 to rent a cutter for two doorways.