For marquetry, I use shop cut veneer, so that it'll hold together while I make the double bevel cut on the scroll saw. So my veneer was 1/16" thick, far thicker than commercial veneer. I suspected that I may get away with edge jointing on my jointer, and I did for the poplar, but it was a stressful experience, half expecting the veneer to explode. When I tried this with the curly maple, it chipped out, sadly, so I tried a new (to me) way...
I started by edge jointing 2 3/4" pieces of scrap oak that I had from a prior project, and then ripped them to equal width on the TS.

I sat these into my workmate, jointed faces up. They span the 2 supports below, and create a level reference plane. I then slid my veneer between the two oak boards, and exposed a small amount of material, as little as I could while taking out the afore-mentioned chip out.

Then I simply planed down the veneer with a low angle block plane. This took very little time, was stress reducing, rather than stress causing, and yielded nice straight edges that I could veneer tape together, and put into the veneer press.
I don't know how many people will get use from this, but I hope someone gains benefit from the idea, thanks.