I am so jealous.... Have you been able to do it cheaply? For us, 17K € would have been due, as there is no fiber optic in the development area. That was too expensive for us.
So if it is as described by , it runs over pppoe. Then you can connect any router behind it. If you don’t want to pay rent, I would get a cheap and robust router and that’s it. If you have a server or Raspi running, it could also serve that purpose.
If the Fritte is to be used as a modem, it can handle a maximum of 300mbit. Without knowing your future connection, FTTH can do significantly more. If it is really FTTH and not FTTB, you cannot avoid a pure suitable modem. In that case, take the Telekom device. Behind that, any router of your choice.
What kind of APs will you use? Are you still with the Develo? If you really don't need all the functions of the Fritzbox, take a look at Unifi usg, edgemax, mikrotik, etc. You can get a stable router for less money.
If the Fritz box is to serve as a modem, it can handle a maximum of 300mbit. Without knowing your future connection, FTTH can offer significantly more. If it is really FTTH and not FTTB, you cannot avoid a pure suitable modem. In that case, take the Telekom device. Behind it, any router of your choice.
The 300Mbit is possible with the VDSL modem of the 7530. Behind the fiber modem, the 7530 can do more.