If I replace dnsmasq with dnsmasq-full, can I delete the odhcp-ipv6only and odhcp6c packages? Does dnsmasq already do everything?
No.
Dnsmasq does not do the ipv6 client role that is handled by odhcp6c
So I can uninstall odhcpd-ipv6only, but not odhcp6c? Where can I find a guide to odhcp6c? Thanks.
You really need to know why you want to prefer dnsmasq over odhcpd for IPv6, there's a reason why odhcpd is developed - dnsmasq is lacking in regards to dynamic prefixes (thanks dear ISPs) and other domains.
I followed the Github page of the Stubby package to configure DNS on TLS. To enable the DNSSEC to be set, the full version of dnsmasq must be installed that also manages the DNSSEC proxy. I understand that dnsmasq-full also manages DHCPv6. But I'm a noob and I do not know if dnsmasq-full acts as a server and client or just as a server. I do not know if a dhcp client is also needed in a router.
At the moment I have removed both odhcp-ipv6only and odhcp6c and everything seems to work regularly with 11 hosts connected to Linksys WRT3200ACM.