One known side effect of unnecessairly importing Compat.jl is this package compiler issue, but it’s a pretty niche use case, so it’s unlikely to be a problem for you Type piracy on `Base` fails incremental sysimage builds (1.9 -> 1.10 regression) · Issue #924 · JuliaLang/PackageCompiler.jl · GitHub
I’m personally not a fan of Compat.jl. It changes the global execution environment for users without their knowledge (if it lands in their Manifest) and it’s basically a type piracy factory (on Base) if used with a lower than latest Julia version.
I would rather avoid adding it to packages unless absolutely necessary. There are a few issues about side effects of Compat.jl being present implicitly in user environments, so I’d rather not contribute more to the issue