“find in selection” is very useful, but at least the way I use it, I only want it temporarily (e.g. while working in one particular selection in one particular document). If it stays toggled it becomes a nuisance that can lead to corrupt data, by unexpectedly failing to make desired replacements. Please consider one of the following to make this option safer and easier to use:
- Have the Option key temporarily enable it while held down (and visibly toggle the icon to make it obvious it is happening). Older editors I have used support this and I love it. Definitely my favorite solution, though I admit it requires documentation for users to discover it.
- Make it temporary. Clear the option after each find, or perhaps after the user changes the selection or switches documents. The former is easy to understand and plenty good enough, but the latter allows one to make a set of replacements within a selection.