OneLogin IdP initiated Logout

[sheharyarn]

I'm trying to get IdP initiated logout to work with OneLogin which uses redirects to send the SLO request. Looking at the source code I can see that Samly only supports POST requests for logout, not GET:

https://github.com/handnot2/samly/blob/110d348dfaca2fbf572ae4c93d770267e0c09313/lib/samly/sp_router.ex#L22

What would it take to get it to work with GET request/redirect? Would simply changing post here to get work? Also, while we're on the topic, is there something like the pre_session_create_pipeline config for logout requests (so we can invalidate tokens or perform some other actions on a valid SLO request)?

Thanks!