I used to use the cladding brush with no problems, switched to the flocked sill brush & it works even better!
As it's not being used at height there's no real issue with weight.
Extra bristles on the flocked sill helps with the clean & the splay of the bristles reduces any risk of clattering painted surfaces with the brush stock... the cladding brush was a bit scarier to use as I think it's a 0 degree brush (I might be wrong on that).
Have used both brushes on mine & my missuses vehicles with no problems or marks on the paintwork.
Hope that helps.