SafeLine WAF — Dynamic DNS Resolution for Upstreams

Feature request: expose Tengine's dynamic_resolve for upstreams
We use upstreams defined by domain names, and their IPs change frequently due to DNS-based failover. Currently, upstream domains are resolved only at configuration load/reload time, so traffic keeps going to
stale IPs until a manual reload is performed — which effectively breaks DNS-based failover.
Since SafeLine is built on Tengine, could you expose Tengine's built-in ngx_http_upstream_dynamic_module? e.g.:

upstream backend_xx {
dynamic_resolve fallback=stale fail_timeout=30s;
server app.example.com:443;
}

This would let upstream IPs update automatically at runtime without reloads, with fallback=stale falling back to the previously resolved IPs if DNS resolution temporarily fails.
Ideally this could be a UI option (per-site toggle + resolver setting) or supported via a custom upstream snippet.