Add / Remove Products from an Account

Hello all
I was wondering whether it is possible to add or remove the related records such as products from an Account

I would like to get that information from another system and have it constantly updated per account. So far I only see there is https://www.zoho.com/crm/help/api/updaterelatedrecords.html method but it only updates the record which is already related.

My idea is that if external information says "customer A has products x y z" and in my CRM customer A has k and x added, I would be able to add also y and z , and I could also remove k. I didnt see any options of inserting or deleting related records.

Am I missing some methods?
Are there other ways to do this?
If not, is it in roadmap?

Looking forward to your replies / comments.
Regards