Don't know about the FP-30 but the whole triple-sensor thing is a band-aid solution for design flaws in most DPs. After all, the acoustic piano only has one sensor per key (per hammer to be precise): the string. So really that's what DPs should have: a pressure sensor at the hammer strike point. But I appreciate that pressure sensors are a lot more expensive than simple on/off switch type sensors, so all is fair.
As far as I've read, despite its 3 sensors the SL88 still only senses the key movement and has no sensors for the hammer. So you have to have the key move almost all the way to the end of its travel to trigger a note.
OTOH the Casio PX seems to have 2 key + 1 hammer sensors. You'll find illustrations online depicting this as well as a different mechanism that only senses the key; one wonders how accurate those illustrations are. Nevertheless, I've tested the hammer sensing on my PX-160 by placing a hard stop at about 2mm under the key (the protruding lip). When I strike the key with enough force, the hammer does fly off and trigger MIDI output even though the key moves no more than 2mm. So I am fairly convinced they've done this right and the hammer strike is being sensed. This is something you might like to try before you buy a new instrument.
3/2 = 5