Help find, or find alternative, or feature request for flac -w flag

[OTTcadwallader]

I have a bunch of legacy wave files of various sorts that I'm archiving, and there's some formats that FLAC converts to a slightly different format with, technically, the same data. But the legacy software doesn't read them properly when restored.

With command-line FLAC, I use the -w flag (treat warnings as errors), and FLAC will refuse to process those files, and I can see that and do something else with them.

With fre:ac, I can't find any way to add that flag to the command line it uses. Is this an option in fre:ac? If so, where do I find it? If not, where can I add it as a feature request? I don't care whether it's a checkbox or just an 'additional parameters' line, just so I can set the flag when processing those files.