After a short period on China stable and beta ROMs, I decided to come back to the latest Global ROM, 7.1.0.0G and I had a very big surprise: I obtained root!
So, after installing latest Global firmeware, a couple of days ago, I checked mroot.flyme.cn and reapplied for root authorization, mostly because my device appeared on that list of devices to chose from (a code and Meizu Pro 7 name, as in the screenshot). This was not the case before installing chinese ROMs, when only two weird alphanumeric strings were showing, with no particular name or phone model. Today, I checked the mroot app and the root button turned blue

I pressed it and, after a few messages, it dissappeared and a short chinese text was shown on the app main page. I went to activate root like the tutorials suggest: in easy mode create a shortcut to root.OpenSystemRightActivity and activate the root function by entering Flyme account password. After the phone rebooted the root capability was enabled, every app I use that needs root works flawlesly.
So, I confirm: root can be obtained on the latest Flyme 7.1.0.0G for Meizu Pro 7 M792H.