I have some custom routing rules that ICMP redirects interfere with, so I tried to disable them by writing 0 to /proc/sys/net/ipv4/conf/br-lan/send_redirects, but this didn't actually work. Neither did it for the bridge sub-interfaces. To disable redirects, I had to write to /proc/sys/net/ipv4/conf/lo/send_redirects instead.
Actually, it looks like setting it on lo doesn't work either. :/ Manually setting it for every interface seems to have (so far). (Noteworthy, setting it for 'all' did *not* change it for other bridges)