IMO, good advice form all .
to the OP : It's a vg question and should not be a concern.
I am installing my new GY ENDU's 'D''s this week. 205 75 15 from the 'C' to the new 'D' . I asked multiple sources (in fact, maybe too many, my DW thinks I need therapy) and ALL said my stock alum wheels can be used from a 50 psi to a 65 psi tire.
I agree the new metal valve stem makes good common sense.
After you do the install, see how the tires wear over time . If they seem to be wearing in the middle, dropping 5 psi might just do the trick and still offer you weight carrying capacity.