Same here, I love the UDM Pro SE. Blocking application layer stuff like QUIC is just a couple clicks away. It has decent intrusion detection and response alongside other easy to configure firewall settings.
Udm pro SE is the best thing I bought.
10g, protect for camera selfhosting which works great, new updates made wireguard first class citizen, and if you want anything more complicated it's just a dumb debian underneath (which I do a bunch of stuff).
When UDM shows you QUIC eats up the majority of your bandwidth you may decide to click to add a rule to block it. You may see a large reduction in overall daily bandwidth as a result. If you watch YouTube you are using QUIC. Certain QUIC vulnerabilities are a 3 or 4 packet compromise.
QUIC connections do not set an upper bound on the amount of data buffered when reading post-handshake messages, allowing a malicious QUIC connection to cause unbounded memory growth.
I like Google Dart and other Google products but I see too many potential issues with QUIC. From my personal experience it has behaved suspiciously on my network.
This is a particular implementation of the QUIC protocol (which is now fixed). Do you think there haven't been vulnerabilities against TCP? Certainly TCP is battle-hardened, but QUIC will get there too.