The big items in that list of performance issues don't seem to have anything to do with GraphQL. They seem to be related to a heavily function style using lots of immutability and the Ramda library. I'd also suspect that these choices are responsible for the GC issues due to lots of allocations for the immutable objects.

I know, premature optimization and all that. But I think at the point where you're going for microservices because of scaling you really should also look into the lower level issues like that from the start. You should notice that the shiny library you're using is 100x slower than just writing plain code. And you should be aware of excessive allocations in hot paths.