I don't think you need to approach fitting tyres with the thought of "perfection". I certainly don't think "Lets get this perfect" when I'm mounting tyres, not even on £1,000 a piece Brand New wheels - I'm more thinking "Let's make this as painless as possible" because I found that tyre fitting is an awful, awful job to anyone who cares an ounce about their workmanship - I still cringe every time the tyre lever bar makes contact on the bare rim when removing an old tyre, or when the brand new £400 odd PZero I'm mounting gets stretched to the point I'm convinced it'll split whilst mounting the the top beading onto the rim. If your tyre fitter doesn't cringe at these moments asking him nicely isn't going to make a hell of a lot of difference to the out come because the fitter just doesn't care!
Come to think of it, despite never damaging a Rim, I'd refuse absolutely point-blank to fit a tyre with the owner watching over my back. Likewise, if the job card read "Take care with rims" I'd roll my eyes and carry on business as usual - I don't intend of damaging a customer's set of wheels and will naturally do my best to not allow that to happen, and certainly don't need a reminder to do my job properly.