@mayank “HTML modules” as a macro is such a cool idea. I agree 100% that it’s a place we should focus in on things like this. The #webComponentsCG sees this as a big next step towards clarifying #declarativeCustomElements API. Converting your blog to an explainer would be a great next step.
Disclaimer: in a recent meeting with implementors we agreed that Cross Root Aria and Scoped Custom Element Registries are of higher priority. Having solid plans for #HTMLModules when they get done will be