Reading sspenst's comment on DEM4, I tried to apply my 2 off in DEM4 in this level and that's the correct one. That is a brilliant route. My 2nd DEM done!
(since 18-2-2023) Can only achieve 598, meh...
-----
(13-6-2023) Seeing alazeh's comment I returned to this one. Initially I thought I lost steps on the left side as it appeared to be the most challenging part, but after too many tries, I can't cut down steps further.
I really lost 4 steps in another room... mehmeh