Question about Ubiquiti UniFi Cloud Gateway UCG-Fiber

Is anyone operating this device directly on a Sunrise fiber optic connection (XGS-PON, Swisscom network), i.e., without the Connect Box 3 Fiber in between? My connection: 10 Gbit/s, XGS-PON, IPoE connection mode. According to Sunrise support, the Connect Box 3 Fiber technically has no bridge mode – so the only option would be a workaround via DMZ with double NAT and IPv4-only. I've read that it should work with an Allnet ISP Bridge Modem XGSPON GBIC (ALL-BM410-XGSPON-GBIC) in the SFP+ port, provided you get the appropriate NSN code from Sunrise. However, as far as I can see, this is only documented with a UDM, not with the Cloud Gateway Fiber. My questions: 1. Does the SFP+ WAN port of the UCG-Fiber work stably with such an XGS-PON bridge module? 2. How complicated was the activation with Sunrise (NSN code, activation)? 3. Does IPv6 still work normally with it? I'm grateful for any experience reports – even those where it didn't work out. Thanks!