I would like to use the /log xporb command to measure XP/hour.

As of now, looking at chat logs, an xp orb event looks like this:
[22:14:48] [main/INFO]: [CHAT] [794976] Experience Orb created @ [127.3, 31.0, 246.3] $

Desired function:
[22:14:48] [main/INFO]: [CHAT] [794976] Experience Orb of value N created @ [127.3, 31.0, 246.3] $

This would allow an external program to be used to scrape chat logs to measure xp/h

Currently lifetime tracker is able to count the amount of xp per hour, i guess it meets your need

It's added in v1.13.0

Thanks!