Question about using web push for an online thrifting store

Hi there,

I’m building a small online thrifting store and I’m considering using web push notifications to bring people back when new items drop or when sizes they follow come back in stock. Before I dive in, I’d love some clarity on best practices and technical limits.

Specifically:

Is there a recommended maximum frequency for promotional vs. transactional notifications so I don’t annoy users?

Are there built‑in tools in VWO Engage to segment subscribers by interests (e.g. jackets vs. shirts) or behaviour (last visit, last click)?

How granular can triggers be – for example, can I fire a notification when a product from a specific category is added or updated via API?

If you have examples or documentation links for e‑commerce use cases similar to a small online thrifting store, that would be really helpful. Thanks in advance!