Win10, will w32tm turn the system clock backwards, or instead slow it down

Great thanks, it seems the answer to my question can be yes due to:

"The clock discipline subcomponent adjusts the time of the system clock to the most accurate time by either adjusting the clock rate or directly changing the time"

I also found these:

https://techcommunity.microsoft.com/t5/networking-blog/how-not-to-test-the-windows-time-service/ba-p/411592

https://kb.meinbergglobal.com/kb/time_sync/timekeeping_on_windows/accurate_time_in_windows

And finally. not sure of ptp status, it seems there should be possible with a ptp client, but not a ptp server. Is my understanding correct ?

If so, any plans for PTP server functionality,

And, this seems to be the programming interface
https://docs.microsoft.com/en-us/windows/win32/sysinfo/time-provider