Equirectangular Perspective Tool

Have you tried following this method: Krita Assistant Tool [Part 4] - Fish Eye Point (5 point perspective setup) - YouTube

But I am all for more perspective tools. I made a feature request recently around a perspective tool update. Take a look here: Perspective Tool Upgrade

If you want to see those changes please vote on the feature.
You can also leave a detailed comment describing what you would like implemented.
Thanks.