I'd say push closer to 5% and more cash... but it's my understanding that putting a price on a share should be held off as long as possible, or if you must, it should be kept lowish for early-stage.

As others have said you don't want to squeeze it too hard because you'd either jeopardize the future of the company or he could just close up shop, abandon the shares and reopen a new business, especially if there are no other current stakeholders to worry about.

1% IMHO is too small, especially considering you hired and ran good staff for 1.5 years, which is a critical time, and are already revenue-generating. At least push for 2 or 3. I doubt the other founder will accept anything higher than 3, but business types routinely undervalue the technical folks that actually build the money machine. ;)

This is the problem with cofounding, though... It's like owning a home vs. renting... it's far easier to move if you're just renting... Best of luck to you

I was most recently director of engineering at a startup for a year (as first employee, not cofounder), hired 3 good people who are still there, then stretched myself too thin with a toddler at home and we had to part ways (this was hard). Might be fun to have a chat if you're interested.