I know you’re trying to be pragmatic, but to that I would say “what’s the point of approvals if they’re going to be bypassed?”
Approvals sometimes have some degree of pre-conditions of “Depends on who’s requesting it?”.
For example, birth right roles (regardless of IGA solution) are given to you from the get-go if you fit a particular criteria, without needing approvals. Whereas if you want to be added to that role (temporary job / responsibility changes), you would want an approval.
i.e. The need for an approval can bit situational…simply because having an approval does / doesn’t make sense in certain situations. You need to look beyond just the object being requested.
Hi all thanks for your responses,
Terry - To avoid the race condition, ideally, removing user based on their ID rather than their index position would be more reliable.
Mark - Appreciate the tip, I gave this a try and getting 400 bad request 
In terms of the use case, exploring options how to add or remove people to a role. You are right, we could also do something similar via access requests.
Either way, good to know our options. It surprises me how difficult it is to add & remove users (via their ID) to a role via API!