I successfully grafted pawpaws this spring.
Neal Peterson told me to do it when it is warm and when the root stock has several leaves perhaps a couple inches long already growing.
I think I did some whip and tongue and some bark. I only had 2 scions so I used very small pieces so I could make several grafts each. I'm in China right now so I'm going from memory, but I had success with maybe 5 out of 8 grafts. I don't think pawpaws are supposed to be especially difficult.
I grafted these to my existing trees that have been in the ground 2 and 3 years. They are Wilson and Pennsylvania Golden respectively.
I have not grafted paw paws but thought I would contribute this.
This is per the fruit fact from CRFG (there is also a link to it below)
Hardwood cuttings are essentially impossible to root, while root cuttings have been variable to disappointing. Some success has been reported using softwood cuttings under intermittent mist with bottom heat (80° F) and supplemental light (14 hours). All grafting and budding techniques can be performed on the pawpaw, but T-budding is not recommended. Chip-budding has been reported to be successful. Scion wood should be gathered while the tree is dormant and kept refrigerated. Grafting can be done in the spring after vegetative growth begins.
Idyllwild
simplepress
jafar
Marsha H
Viron