Nice catch @Matt S , my reply was geared toward stitching with the transition pieces like the card holders on the top side.
@KennethM , seeing you want your best looking stitch on the exterior of the wallet, I understand why you want to stitch this section with the card holders face-down.
In this case I would suggest stitching past these transition using the hand-wheel. The feed dog is much harder to jig, but in this case a piece of leather wedged between the card holders would likely work.
If you cut the jig piece to fit 1/16” off your stitch line to the top edge, you can ensure the piece is aligned with the top edge so it doesn’t get sewn to your wallet and it doesn’t slip away causing the feed dog to miss it.
Or skip a jig altogether and handwheel over the section. You can match you stitch length to, let’s say, an 8 SPI overstitch wheel spacing and use that overstitch wheel to give you some guide marks as you handwheel that section. A little extra insurance that you’re not getting short stitches as the feed dog works to jump the transition.
And an added bonus is that overstitch wheel can also be used over your finished stitches on the bobbin side, so the deformed leather from the needle puncture hole is inverted giving you a better looking underside stitch line as Matt S suggested.