I regularly run 25mm of riser. Obviously, the less, the better.
The Hammock baseplates look like they have about 20mm of built-in rise (at 50 degrees versus Caliber 2 according to my empirical measurements) and the Riptide Tunnel Risers are 14mm thick. That’d be over 34mm of riser which is a lot but not completely absurd. It’s right on the border of absurd, though…
(This is all on 107mm and 110mm wheels)
I’d run it. In fact I might be using tunnel risers with a Hammock very soon myself. Hopefully it’s good.