Stopped doing it as it's too much hassle, customers would ring up months down the line saying weeds have come through and that the sealed joints have sunk. Don't get me wrong we did the jobs properly. Others on here can vouch they apply properly too and still be of the same opinion.
Blocks are disturbed from the weight and vibration of vehicles.
I read similar views a couple of years ago just like you're doing now.
All the above coupled with the weather we have, a guessing game of when you can return to the job to sand and seal, it can jeopardise other work and/or your schedule.
I'd rather go out cleaning all day for £300-£500 and not worry about having to return and apply sealant and worry if the customer is gonna complain months down the line.