PL21 STD vs Local Altimeter Altitude Hold Setting

[SkyChicken]

Hello! Loving the CL650. Had a question about the implementation of the PL21 into the sim. I've never flown the PL21, but a friend of mine who flew KA350s with the PL21 in them noticed something about the system when I was flying last night and streaming it to him. He said that they'd predial the local altimeter, then unselect STD while in the levels, just to make that one less thing they have to worry about while passing 180. The PL21 then apparently will bump your actual altitude up or down, but remain holding the new adjusted value, e.g. you're at 390, predial in 30.22, then deselect STD. Your altitude bumps up 300 feet due to the pressure change, but it will hold your new altitude of 39,300 feet, so as to maintain that altitude while pre-TOD. Your descent then starts, and you don't have to worry about swapping to the local meter once you pass 180, or whatever your transition level of the day may be. Is this a known/deliberate choice? Or has it not come up because we normal folks don't set a local meter until crossing the FL transition boundary? Thanks!

[ois650]

Not sure why his company would pre-dial and then select local pressure while in the levels. Seems odd as they're now reading a knowingly incorrect altitude value.

The behaviour of the ProLine 21 Advanced that features in the Challenger is correct.

Kind regards