spring-onion
Well, I almost had a heart attack, still may.
I closed the browser window and VPN then went to turn off the Pixel, got a warning that the bootloader was still unlocked, didn't lock it and turned off the phone then restarted it.
It opened up to the "set up your device" page so a factory reset/cache wipe (I'm a noob so forgive me if I don't have the terminology quite right) had been done.
Went through skipping everything, including WiFi connection, then to Developer options...and OEM unlocking was greyed out.
It's taken me 2 weeks and 3 phones to get one that wasn't greyed out.
Then I remembered while trying to sort out the first 2 phones having read somewhere that it can be greyed out because it's already unlocked.
I think the download finished while I was typing this, the progress bar is completely blue but there was no notification, unless it flashed on the computer while I was going this on my other phone.
I'm going to click Flash release and see what happens, here goes...
The Pixel is flashing off and on, fingers crossed