Answer
In most cases, no — an IFS-defined mandatory field's enforcement logic lives at the server/database layer, not purely in the client UI, so even if the mandatory indicator is somehow suppressed on the client side, the underlying server-side procedure call will still reject a save that's missing that value. There's generally no supported configuration option to make a genuinely IFS-mandatory field optional. If you have database-code access and a specific, well-understood business justification, you would need to examine and modify the actual server-side procedure enforcing that specific mandatory check, which is a genuine code-level change rather than a configuration option.