What you want IINA to do:
Replace its own symbols with SF Symbols.

What IINA does currently:
INNA recently updated its symbols, but I prefer if it used the SF Symbols like the rest of MacOS.

Why you think this should be added:
MacOS Big Sur is getting Sf Symbols system wide. Every Apple app and a growing list of third party apps already use SF Symbols. Using SF Symbols would make users more familiar to the interface.

Examples of other projects that have something similar: