I have a Flymap L as a removable device, and 2 years back I opted to add Synthetic vision. It is a GPS-based system (no FLIR camera for real-time). I have not flown inadvertent IMC but the system is fantastic, particularly when flying around the Scottish Highlands below the peak tops.
It is clear to me that this would be a very, very useful tool for IFR / inadvertent IMC.
The system would be even better if it were fully integrated into the aircraft avionics package - which it can be - but that option proved far too expensive so my system remains as a stand-alone running power from an auxiliary outlet. I did check, but (for example) to add airspeed indication you need to break-in to the pitot vacuum line and that is a no-no without soooooo much paperwork and cost. So I don't have a single screen which includes airspeed (I do have groundspeed), and I have no engine data (which can be shown) and the sensor for the AH is not mounted in the best place (under the mast) because that would require the running of an additional wire back to the box, so the sensor is further forward than is ideal for the unit.
Unfortunately, the system of regulation designed to keep aircraft safe is one of the reasons why development of safety features proceeds so slowly.