It's secure to open UDP 443 port for QUIC protocol?

Hi all,
My IPFire firewall configurations drop any connection by default. I only opened the ports needed for the Forward Chain. Everything works fine, but for a while I noticed many connections on port 443 udp.
After investigating the issue, I found that this port (443 UDP) is used by the QUIC protocol, developed by Google and implemented in Chrome browser for faster connections. Anyway if the firewall blocks this traffic, the connections are redirected to TCP port 443.
What do you think? Is it safe to open this port? If I don’t open it, can this be reflected in the speed (latency) and reliability of the connections?
Appreciate any opinion. Thanks in advance.