Can I use these techniques while developing an embedded public app?

Shopify Apps
1

Hey Guys!

Right now i am developing an application which will be an embed public app.
Sofar i had couple of questions about what can and what can’t use in a node/react application.
May i use the following “tricks”?

Frontend: Store search query parameters into a client’s browser local storage? If can’t is that acceptable, if i don’t use the query parameters from the url?

Backend: Write/delete/modify in the app files? For example create a json, which makes the application stateless?

2

I had no issue during the review process.

Couple of times the application has been declined, because the app could’nt handle the GDPR webhook events.

So my application had approoved in 1 week or so.