Nice!

In order to squash the "warning: profiles for the non root package will be ignored, specify profiles at the workspace root:" warnings, you could remove this section from all the nested Cargo.toml files and add it underneath the [workspace] in the root Cargo.toml:

[profile.release]
opt-level = 3
debug = false
rpath = false
lto = true
debug-assertions = false
codegen-units = 1
panic = 'abort'
incremental = false
overflow-checks = true

All the workspace members will then use that profile for release. It would be good to restrict it to the wasm target but that's not possible yet: rust-lang/cargo#4897