Removing Exemptions from CSV at scale

[robsissons-contino]

We have a CSV file with over 21k (temporary) exemptions.

When doing a deployment we encounter a large number of exemptions which are no longer present in Azure due to resources being removed. This results in a long list of errors (see below examples) in our deployment step.

Exemption 456(/subscriptions/xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx/resourcegroups/rg1/providers/microsoft.web/sites/site1/providers/Microsoft.Authorization/policyExemptions/Exemption 456) Policy Exemption error 404 -- {"error":{"code":"ResourceNotFound","message":"The Resource 'microsoft.web/sites/site1' under resource group 'rg2' was not found. For more details please go to https://aka.ms/ARMResourceNotFoundFix"}}

What is everyone's best way to manage this and remove the exemptions from the CSV at scale?

I have written a couple of functions to interrogate the deploy output and gather the exemption name, then parse the CSV to remove the lines but feel like there must be a more elegant approach?