Start rtsold immediately after dhcp6c sends it requests
I suggest to remove the 2 second sleep before the rtsold is started after a request in the "don't wait for RA"-codepath. Some ISPs only send the router advertisement when they send their dhcp request, in that case it might be too late when rtsold is started.
It was added in 718cbc2d3921627e9767e59d539386c843dffcc4 but it's unclear why it was added. I've been running it without the sleep and it's working perfectly fine and that is allowing me to get router information where I previously couldn't.