We do not provide direct user support for other's end user products (with the exception of ours end-user products, of course). If Affinity takes money from its users, they should be engaged in support without throwing this ball to us.

LibRAW is targeted to developers, we're ready to provide support for Affinity team, but they never contacted us.

Please send this link to Affinity team: https://www.libraw.org/extended-support

Also, you may just wait: Panasonic DC-S5 II is supported since March, 2023; We'll release it in public snapshot according to our release schedule: https://www.libraw.org/#updatepolicy