And speaking of front-ends, there's some funky stuff going on in the bladeRF's:
C331, the receive switch blocking cap, is 6.8pF. At 300 MHz, it has a capacitive reactance of 78 ohms. Unless there's a good reason for that (e.g. RF tuning), that's pretty irregular. Typically switch blocking caps are chosen to have very low reactance at the frequency of interest, so as to minimally perturb the 50 ohm environment of the switch port. The reference curves in the switch datasheet were taken with 47pF caps.
Another oddity: the switch control lines are bypassed at the switches with 8.2pF. The bypassing itself is good practice, but again, I question the value. At 300 MHz that's not a very effective bypass. Bumping up the cap values and adding a series element, a ferrite bead or even a resistor, would provide better rejection of environmental RF. My guess is that those traces are run on the surface layer, unshielded, as well.