Custom invite permissions are cool and should be used when you are sharing your bot to other
users.
Wherever this comes with some pitfalls:
Let's use an all-purpose bot example.
You have a funny bot that currently is only sending cute cat images.
So by following the principle of least
needed privileges you are not giving it any other
permissions than sending messages.
One week later you decided to add moderation features to your bot
- like kick and ban.
You added correct function code, and boom - newly added commands are not working.
Why?
Because in order to update your bot permissions on other servers,
your bot needs to be re-invited to all servers.
That's why you need to consider what permissions
will be needed for your bot in the future because changing it
later is very hard.