I always leave the neoprene on until I'm on my way down or on my way up.
I'm suggesting that after a day of this treatment, much less a week it's very probable that my cover has enough salt embedded in the cover that it would leave micro scratches on the acrylic dome. Done over a period of time, pretty soon I've got sand paper.
Except that the salt won't accumulate into "sandpaper" over time. Sure- you'll probably never get all the saltwater out of the neoprene with just rinsing, but you'll wash out the vast majority of the salt every time. Otherwise, putting on your your wetsuit would be horrific after several years... and when's the last time you saw any salt buildup on your wetsuit?
An anecdotal story - I've been keeping saltwater reef tanks for more than 15 years now - mostly with acrylic tanks, and there's always the concern about scratching the acrylic. (Recent picture below of my current tank). In 15 years, I've never had any instances of salt causing scratches on acrylic. Sand and rocks, yes. Salt, no. Which leads me to believe that the hardness of salt is less than the hardness of acrylic. I'm not saying that it's not possible, but with as much as I deal with salt and acrylic, you would have think I'd have seen evidence of salt scratches by now...

Either way, I think the risk of scratching by a boat operator or other divers is far greater than the possible salt buildup.