For example, if the approver has left the company, or is out of the office and unable to approve the document and it needs to be approved immediately.

This would be an outstanding feature to enable. Suppose a document has been drafted and an approver is unexpectedly called away from the office. In that case, there is no option to correct it at the document level, requiring that the entire document be re-drafted in a template with an alternate approval workflow. This is both time-consuming and cumbersome for our team.

We especially have the issue in the case someone leaves the company.
A better solution to this would therefore be to have a central approval group manager module.

The main problem for us is that an approver is hardcoded into any document created from a template with an approval flow.

Even though we update the template, that user will still be the only one able to approve the document.

With a central approval group manager (like the role manager in PandaDoc) you'd be able to create and manage groups for all documents where the approval groups have been applied to.

And when something changes - like if someone leaves the company, you won't have to update the approval flow on all templates individually.

Ideally, if on vacation, to have the settings allow the temp-approver to be assigned from "x" date to "x" date.