Not my first choice either but give the customer what they want.
If you end up doing this really look at the support requirements. Table 352.30(B)
1/2", 3/4" and 1" all require
supports every 3 feet
Even 4" requires a support every 7 feet.
These supports "shall be fastened so that movement from thermal expansion or contraction is permitted."
This means do not use something like a EMT minni or a standard uni strut clip, you must use proper PVC supports that let the PVC slid through them.
Expansion fittings, plan on a lot of these.
IMO it is tough to make PVC look good over a long period of time.
Depending on building construction the support requirements could break the budget.
Say it is a steel truss building that has a 5' to 6' spacing, how will you support every 3'? eek: