On my system there is a delay of about half a second for the infotips to appear on a selected image and I find it is not a problem. However if you use windows search to select images - as I do a lot - the situation changes, and you have to wait for the infotips initially to build in he search display lister.
Obviously the infotips are fired by the metadata in the image. No metadata, no infotip! Which is what brought me to write my script to add metadata to files.
Sure Opus has its own interface for adding this metadata, and for the odd image it is fine. But you try adding comprehensive metadata to 40 plus images on a daily basis, and its limitations soon become apparent. But, hey, Opus is not an image metadata editor.
I only offered a view of my metadata entry script solution as an encouragement. I would not advise anyone to copy it as it is truly bespoke for my needs and saves me hours of work every week.
As far as I can see you can add info tips to any file that contains metadata. They are particularly useful for music files, I find. Start hacking at the help files. Infotips in Opus is far,far, from rocket science.