I corrected your inaccuracy.
I gave a detailed reason why, named the relevant RFC and provided a link to a thread covering this in lots of detail for the zyxel decides.
just because I have not covered every single possible variation in detail...
My point was the only variation you did describe isn't the limiting factor.
Anyone on OpenReach NGA (FTTP, FTTC, G.Farce, likely other products) can use 1500 MTU with PPPoE.
The customers hardware being the only limiting factor. In many cases the hardware supports it but just isn't supported by the firmware.
With respect, maybe you could be a little less abrasive in your contradictions of people who are only trying to help.
I disagree, and that wasn't my intention.
This is by far the most posted on/viewed Zyxel thread on these forums.
My intention was only to correct any inaccuracies.
I usually thank people who correct me, take the time to educate me on why, and tell me my hardware can do what I thought it couldn't.
Oh, and welcome to the forum