List Of 5th Gen Custom PID's?

If no one has already, it should be constructable from a searchable gen 5 Repair Manual, by searching for the string "DATA LIST / ACTIVE TEST".

The string will match multiple times (probably a couple dozen times or so), once for each ECU in the car that has live data to supply, and you will find the PIDs from that ECU in a table immediately following under the heading "DATA LIST".

At least, that's the way the gen 3 manual is organized, so probably will work in gen 5, unless they've changed the headings slightly or something, in which case a slight adjustment might be needed.

Those tables will not give you the PID address / bitfield / arithmetic conversion information that you would need to actually program a scan tool to retrieve the values. Those details are what scan tool manufacturers have to either license from Toyota or try to reverse-engineer. But they'll tell you what all PIDs are available and what they mean, which you can compare to any scan tool's list to see if the coverage is complete.