[LargoLasskhyfv]

There are other ONs, doing away with the sharedness of the GP. Giving you an exclusive ptp 'BIDI-link' into the ISPs next switch.

https://duckduckgo.com/?q=bidi+sfp looking like this:

https://www.fs.com/de/products/39196.html fitting to this interface specification from the ISP:

https://www.wilhelm-tel.de/schnittstellenbeschreibung which is AON also known as 1000BASEBX20-U.

Just have to watch out for the right wavelengths/colors for TX/RX(transmit/recieve/upstream/downstream)