1mm off?.......
Go straight to the cupboard under the stairs in the naughty warehouse. 😝

I wouldnt stress about it, especially if it is on the Bass side.
As for the tape, I reckon everyone has done that at some point.
I use sellotape these days, being so thin it makes no difference if it is left on.
Only thing I am wary of is that it is only 2mm wider than than the rout so I end up with just 1mm either side.