Bob - et al what you propose works with FRAMED cabinets but typically not with frameless type. The kind Mr Fin is building.
The countertop , even if it is "built-up" and lets the lip hang over your 3/4" stretcher would then capture the drawer fronts and door tops so that opening them is impossible.
That 3/4" in a framless install will cause a lot of dishwashers to be uninstallable because they won't shorten to 33 3/4" install height.
The biggest issue though, is what I've already spoken of: the DW panel will not align with the adjacent panels and the boss, client, designer , architect, mother in law ect... will notice and complain. Trust me.
On frameless const. there is 1/8" from the underside of the countertop and the tops of the doors / drw. fronts. The only way to use a 3/4" stretcher like you advocate requires :
1. You have a cabinetry panel made for the dishwasher.
2. The dishwasher accepts said panel.
3. That dishwasher is capable of installing at a height lower than 33 3/4". This generally means a european model, but thre are a few domestic brands too.
If you don't meet all the requirement then there's likely to be complaints.
Regarding the floor deflection - the details are what matters. You could well be in the L/400 range with 16" x 16' 2x10. If you really have 2" x 10" joists out of fir, spruce or southern yellow pine.
you could also have a floor with well under L/200 if you've got unknown species, 9 1/4" tall joists x 1 5/8" wide and they've got a lot of knots and cracks in them.
Oh, And I disagree that the DW must be connected to GFCI circuit. Not required anywhere I've worked on a project in the last 10 years. Is that a new NEC amendment for 2017 ?