Precompiling package extensions?

Is it possible to precompile code in package extensions with PrecompileTools.jl?

Say I have a package Foo.jl with an extension FooMakieExt.jl for Makie.jl recipes. I would liike to write precompile workloads that would be triggered whenever a Makie.jl backend is loaded in the session.

I already use PrecompileTools.jl to precompile code in Foo.jl. But the question is how to deal with weak dependencies? Is there a way?