Duckstation(one of the most popular PS1 Emulators) dev plans on eventually dropping Linux support due to Linux users, especially Arch Linux users.

https://reddthat.com/post/46825035

Just fork it lol
Would have to go back to before the license change in September 2024. The current license basically forbids forks, from my reading.
You cannot forbid forking a public GitHub repository, per their terms of service
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Yes. The license doesn’t technically appear to forbid forking, just sharing the fork.