You mean https://www.mulliner.org/collin/ttdnsd.php ? It uses LD_PRELOAD instead of iptables AFAICT. I am not sure it can do application specific routing by itself. solutions that use LD_PRELOAD are said to be easily circumvented by the tunsocks author. I don’t know if he meant accidental or deliberate malicious actions. If we are talking malfeasance then we have bigger problems. Also we wouldn’t ever install a malicious program on purpose so it s a moot point.
IMO tunsocks is our best bet since it does all the program specific namespace redirection leg work. Though it does not support UDP, it is able to encapsulate DNS with TCP and forward it to the socks server you want.
(tunsocks should not be confused with tun2socks - the latter a part of a feature rich suite known as badvpn)
Depending on the re-write difficulty, I wouldn’t worry much about language safety because it runs in the WS.