How can one use a custom serializer in a BackwardsCompatible serializer?

[pmbanka]

BackwardsCompatible serializer uses Comapct and Default serializer. Is there a way to use some other (custom) serializer in there, like CamelCaseSerializer in place of Compact?

Maybe current approach to serializers (modules + SRTP) allows for it, but it is simply too hard for me to reason about.

I think creating a composable serializer would be easy if some common interface for the serializers were introduced (in place of SRTP).

type ISerializer =
    abstract member serialize<'T> : 'T->string
    // etc.

type FallbackSerializer(main : ISerializer, fallback : ISerializer) =
    implement ISerializer with
    // etc

What would be the downsides of such approach?

[pmbanka]

Any idea how to do that? I just realized that the Compact serializer sets MissingMemberHandling.Error, which is something I would like to avoid

https://github.com/Microsoft/fsharplu/blob/master/FSharpLu.Json/Compact.fs#L241

and still be able to use BackwardsCompatible serializer.