Loading mods with -ServerMod presents a PBO error for clients when attempting to connect when the running PBOs on server side are signed but without a key added in keys directory. This behavior is not intended, the point of a -servermod parameter is to bypass and ignore signature verification against clients.

The kick message error is also ambiguous as it doesn't report a specific file path of a PBO but rather the entire directory the -ServerMod=@Mod defines.

Load a signed PBO via -serverMod without adding the key in keys

Mods loaded with -serverMod should have zero verification in regards signature or client mod list matching.