I also agree.I've just spent a month tracking down an issue where IPv6 networking connections hang. Using Debian buster, 4.19.0-6-amd64.
Machine carries a full IPv6 table, received via BGP. About 80k routes. Symptoms were BFD dropping out. Connectivity hangs.setting net.ipv6.route.max_size to 2147483647 fixed all issues. (aware this might be too big)
Later kernels (5.4.11) cause a dmesg when full. Tim
