Almost all my civilian career was spent in VFR only Part 135 (charter) operations. I'm retired now.
The last 20 of those 48 years, even the VFR single engine aircraft had basic IFR gauges.
I worked single-engine VFR HEMS day/night for the last 16 years. The ops manual insisted that an IIMC event would be handled by a straight ahead climb to a safe altitude. It's completely contrary to one's strong initial impulse to crank around in a 180 or descend to visual. But the policy works, if you think rationally, get your instrument scan going and accept the situation. I think the mnemonic was recognize, admit and accept, climb, confess and comply. Or something like that.
In the 48 years, I flew about half my Vietnam tour year flying nights, providing illumination with aerial flares. You want a vivid spatial orientation demonstration? Fly over an aerial flare at night, in and out of the clouds- the Sun is underneath you. Trusting the gauges was empahtically reinforced early in my career.
But I digress, I flew "light twins", AS355s in the Gulf of Mexico on contracts with minimums of 300' ceiling and 2 miles. 130 knots in those conditions is idiotic, at best you have a minute to visually acquire, recognize and divert around an obstruction. The 355 I flew cruised at 120 or so, and a key cue that the conditions were dropping below minimums was the urge to slow down. Even a 120 in perfectly flat terrain is pretty fast.
I never had to complete any of the IIMC flights under IFR, offshore or HEMS. The climb and a short IFR flight to VFR conditions every time. I did land en route for weather, precautionary weather landings, including the occasional overnight dozens of times. The property owners, neighbors might be surprised, local law enforcement might show up to offer assistance, but I was never ever officially questioned, investigated.
I am curious about the last few minutes of the accident flight in which no, or very little communication between the pilot and ATC were reported. Was that to low for radio or was the pilot task saturated? If so, with what challenge? An iPad running Foreflight is a great tool, but it's also a distraction, diversion of attention at what I suspect was the critical point of the flight. Had he engaged the autopilot while he "Foreflighted"? Was there a discussion as to continuing, the passengers had a schedule, were expecting the service they hired? Were there other aircraft issues? If the pilot did not fully understand the autopilot's operation, was he trying to get that under control so he could have that assistance? Was the final climb and the descent the point at which an autopilot operational issue used up the last of the flight's time? Or, did whatever other issue running the last 4, 5 minutes finally cause a loss of control?