eclectic-coding PRO said 6 months ago on Hotwire Combobox :
Nice video...

I have addressed the issue with using third party stimulus controllers as well. Glad to see you covered the issue.

What I do is create a new file: for third party controllers and include in application.js:
import "@hotwired/turbo-rails"

import "./controllers"
import "./controllers/third_party_controllers"

then I can add my third party controllers:
import { application } from "./application"

// Load third party controllers
import Flatpickr from "stimulus-flatpickr"
application.register('flatpickr', Flatpickr)