Ability to disable deleting comment

The requirement comes from the standards the company I work for has to comply to (mostly Aerospace and Automotive are relevant for this). If we want to use Bitbucket Server's pull-request feature in order to conduct formal reviews and record findings, those findings must not disappear. So if an external auditor comes along and wants to see how we work and then sees a "big throbbing" delete button next to review comments, that's not really great.

There appears to be an event for comment deleted, but it is not cancelable.