@Man Eating Duck - nope, no more squirrels left in the tree on that one
Lets just say that finding agreement on how Find/Replace should work is a contentious topic

. I know exactly the use case you mean - for instance you put together a "sentence joining" regex, hit the replace button, get taken to the next occurrence on some other tab in Sigil, and want to know whether that last one worked or not if you can find it again. That said, the other 99% of the time I am perfectly happy being taken to the next occurrence...
The only thing I can suggest for now is restrict yourself to the current file (via dropdown or ctrl+click on Replace button) so at least you are on the same tab. Then use undo/redo to get taken back to where that replace occurred and see the effect.
There is no universal standard on Find button layouts. Every single app does them a different way. And there is resistance to putting more buttons on the Sigil one (as they take up a lot of space and add visual complexity). Hence why we have things like ctrl+clicks, and regex options in the Search menu. There is a few ways that an option "could" be supported (without needing a button) but it needs some discussion as to the if/where/how.