Overthinking isn't always a bad thing
Robert, don't abandon your drilling idea.
The same thing has been suggested for the new dumbed-down clothes washers that have restrictors in their hot water inlets (rendering "warm" water that's barely tepid), and has provided good results. I see no reason why you can't do the same for your dishwasher's restrictor, except it may not be as easy to drill a new relatively pliable restrictor as opposed to a hardened old one.
Ralph
Robert, don't abandon your drilling idea.
The same thing has been suggested for the new dumbed-down clothes washers that have restrictors in their hot water inlets (rendering "warm" water that's barely tepid), and has provided good results. I see no reason why you can't do the same for your dishwasher's restrictor, except it may not be as easy to drill a new relatively pliable restrictor as opposed to a hardened old one.
Ralph