Yes I'm aware of that....he has to leave by 14 May. The Immigration advice is in order to preserve the said extension he will have to have a re entry permit.
The bottom line is the OP has to leave Thailand by 14th May or risk over stay and all that entails.
He is of course free to re-enter the Kingdom and start the process over again having preserved his "entitlement" with a re entry permit. 🙂
It clearly states extension of stay is granted up to 14 May 2023 (60 days from 15 March 2023).
It states clearly you have to leave the Kingdom within that time period otherwise you will be prosecuted.
It advises you to obtain a re entry permit to preserve the permit.
And to report every 90 days.
So it would be prudent to obtain a re entry permit (1000 THB) by filing a TM-8 with Immigration before you leave and return to Thailand to start the process again.
Ask yourself what are the Immigration restrictions in your country of citizenship and whether they compare.. But don't worry Jo....you leave enough of a digital footprint to be traced. 😉