Short/long answer: depends on implementation.
What is lb-local then for? I can now 100% confidently prove it's not working and replicate the issue.
What is typical local traffic? Mainly DNS requests, NTP updates and maybe some other updates.
DNS fails 100%. ping without specifying -I fails also 100%. Ping with -I works (as expected).
Main problem is DNS failing. All DNS proxy requests from LAN clients as such fail too and impact LAN clients. But it's not just DNS that needs to be fixed, all of locally generated traffic should obey LB tables when lb-local is enabled. If lb-local is disabled I'd expect locally generated traffic to obey main table.
