DD-WRT for AR300M NAND available an restore bac by Uboot Web UI possible?

Technical Support for Routers
2

Yes, but the last time I checked, DD-WRT did not support DNSSEC / DNScrypt so I dont see a compelling reason to use it since there is no package manager.

https://www.reddit.com/r/networking/comments/8emrwb/hijack_of_amazons_internet_domain_service_used_to/

https://blog.thousandeyes.com/amazon-route-53-dns-and-bgp-hijack/