Request a new feature, or support for a camera/lens that you would like to use in Capture One.
Using the keystone correction function, it is important to set the anchor points precisely. Sometimes they are difficult to recognize, or the image structure is very complex. It would help a lot if a magnifying glass appeared and enlarged the image section as soon as you move an anchor point.
Requested here a while ago: https://support.captureone.com/hc/en-us/community/posts/9740851622557-Keystone-tool-Loupe-showing-position-of-adjustment-points
... and for the straighten tool too.
https://support.captureone.com/hc/en-us/community/posts/15181162902685-Offer-the-option-to-automatically-activate-a-loupe-when-positioning-straighten-and-keystone-tools