So, I have followed up with the devs about overrides in 19.2 and there are two important things: 1. It is possible to do overrides with TS files. (Local development works on TS files.) 2. There is a bug in the JavaScript Gulp task that requires patching in order to make it work (this will be corrected in 20.1) EDIT: To be absolutely clear here, we don't recommend TS overrides except in very rare cases. You should extend or wrap where possible. Also this only applies to frontend TS; backend TS cannot be overridden.

Interesting, what is the bug? I am curious, a few weeks ago, I needed to rearrange all the my account menu entries, rename them and add new ones (this is possible via extensibility API but not the first one), so I had to override the Header.ts in order to do that, I have deployed that and it is working fine.

Ah, perhaps the issue specifically affects views then. Basically, you override a view and then go to view your local site and you get something like this

require.js:168 Uncaught Error: Module name "Header.Logo.View" has not been loaded yet for context: _. Use require([])

wouldnt it be better to extend the ts file? Would you do it in ts or js?

Yes it is!