Ikea Pax wardrobe flat against the wall or with a gap?

Hi!
I recently bought a white Pax (200x236x58 WxHxD) and started assembling it yesterday. So far, no problem. Now I need to anchor it to the wall at the top. Problem: the baseboards/ skirting boards behind it. The baseboards prevent the cabinet from sitting flush against the wall at the bottom. Because of that, the body leans against the wall by itself at the top. I am now a bit undecided about what to do.

Either I remove the baseboard and push the thing all the way in. Advantage: no risk of accidentally knocking out the only nailed-in Pax back panel. Disadvantage: no ventilation behind the cabinet.

Or I leave the baseboard in place and use washers at the top to compensate for the distance to the wall. Advantage: ventilation; disadvantage: vulnerable Pax back panel.

What would you do and why?
And which screws would you recommend? There were none included with the cabinet.

Normal 40mm MDF skirting boards, basically. No idea how thick they are. I'd say about a finger's width. Slats would also be conceivable, but with washers I am more flexible. I have the impression that the wall is not perfectly straight.

2 options 1) The bracket for the wall has 4 holes... if you put the holes in the last position and then plug them 2) saw off the left and right corner under the cabinet with a small saw so that the cabinet sits over the strip on the wall... but since the cabinet should breathe (air flow due to moisture / mold) I recommend option 1. Our 3m Pax "monster" also stands without being attached to the wall... and that in apartment No.3 without damage / tipping over

Variant 1 has only one "catch": the bracket is inside the cabinet and therefore cannot be used as a spacer. For that, the back panel would need to be cut accordingly.