Being non slip rubber, they might make it more difficult for your pillion to get on and off. I see two reasons..... (1) The little bit of extra height means legs need to be lifted higher to clear the pannier making boot strikes more likely, and (2) being non slip, if a boot does touch the rubber, it won't slide, but catch making mounting and dismounting even more difficult. Your proposed panels don't look to bad, but do they look better than a few fine scratches?
I had a signwriter cover the tops of my ST1300 panniers with "signwritere clear" sheet, which protected the pannier tops from boot strikes, and I've done the same with the Beemer. However, a good polish will get most boot marks off the paintwork, and a decent auto painter can colour match/repaint the lids every ten years if they get too bad, so doing nothing is an option. Talk to a signwriter about getting your acetate sheet off, as they are always removing such material from painted surfaces (My son was a signwriter)