More info on IEEE 1588 support

Dear all,
I would like to have more information about the PTP support the Portenta X8 offers before considering the purchase on one unit.

Could it the device be used to make a PTP grandmaster clock, e.g. by hooking to the device a GPS shield?

What would be the output of sudo ethtool -T eth0 from the device?

I'm looking into a project like this one for the Raspberry Pi CM4 but with the Arduino instead, as the CM4 has been out of stock for too many months now.

Thanks,
Marco.