Pe90X, Konis are only rebound adjustable.
OP, have the same K/E set up and I used the e36 M3 stops in front, without cutting them. They are significantly shorter than OEM. Have had no problems even on nasty winter ice-rutted roads.
How much did you cut down the front stops you are using now, and which part did you use (top or bottom)? The top is thicker and harder, the bottom is tapered, and much softer.
BTW the Eibach instructions do recommend cutting bump stops, I cut the rears one inch and used the e36 in front.
I would also SOFTEN the front susp to only 0.5 turns from full soft and see if that helps. You can get a phenomenon called jacking with too much rebound damping where the susp does not fully extend and then it is too compressed for the next bump. This would happen more when very cold. I'd try that first before doing anything else.
I have read that the adjuster on these Konis is not exactly linear, so that at 1.5 turns off full soft you may be running max stiff or very near it. Anyway try running full soft (at least 1/4 turn off the stop).