Void the warranty? Heck, walking on an 84F floor isn't exactly comfortable either! If you need the wood to be 84F to get enough heat into the room you have a VERY lossy room indeed! But you needn't worry about heating the wood up too quickly, given that it's a slab- the thermal mass of the slab inserts a huge ramped delay on the surface temperature (which is why PID-algorithm thermostats with both floor & air temp sensing are often needed with slabs to keep room temps from over/undershooting the setpoint.)
In the lossiest radiant zone in my house the surface of the wood floor never gets warmer than ~ 76-77F (when it's ~0F outside), but since it's a staple-up with 1.5" of plywood subfloor I still need ~130F water to get it there. (Had it been installed with the tubing in the upper layer of subfloor it could probably run on ~100F water on design-day.)
If you really want to keep the water temps down & responsiveness up even with, a dual-stage thermostat & a second hydronic loop for that zone, making the slab the primary radiation, and radiators (or baseboard- preferably cast hydronic rather than fin-tube convectors) the secondary will give you quick warmup response and lower operating temps. Panel radiators & cast-baseboard radiators can be on the pricey side, but they're wicked-comfortable compared to fin-tube. Fin-tube kinda craps out below ~110F (even dust-kittens can dramatically cut into it's very-low temp performance), but cast baseboard still does A0K with radiant-slab water temps. But as long as the slab can deliver the heat to the room through the somewhat insulative wood flooring there's not much incentive to go there.