Well, my initiall starting issues were with stock WR cams.
Then I adjusted the CO for perfect e-start still with stock WR cams.
After that I swapped in '05 YZ cams (intake + exhaust), trimmed the decomp pin and the bike still starts as perfectly as seen in my vids.
The only aspect which heavily relies on compression or more precisely the reduction of compression (decom pin) is e-startability:
Stock WR cams work great, in-gear + e-start.
Stock YZ cams kill e-start due to too much decomp.
Grinding down YZ decomp pin to WR decomp pin behaviour
(as describe in another thread by me) did restore peerless e-startability .
At least I can say it wasn't me who let the cat out of the bag!
I also noticed my 450FX starter spins with a bit more authority than my 13 WR 450 I can't wait to put my lithium battery in there to see how it starts.
I bet that even if your decompression mech is a little on the heavy side the bike still starts easier when it spins a little faster.
My dealer said they do their "modification" to every new bike they sell that has issues with e start (mostly WR) free of charge during setup and every bike they sell no longer has issues with starting. Maybe that's why mine starts so easy. But I do not think they discovered what the cause was yet when I bought my 2013 wr from them.