Not sure if this is known. Perspective components custom property scripts and Vision Power Table Extension Function scripts are not searchable via the Find/Replace tool in 8.0.10.
I just placed a custom property and attached a propertyChange script to it and I was able to locate an expected String.
We’ve had lots of users report that they were unable to locate expected values in Perspective because they had failed to modify the search options to look in Views which were not open at the time of the search. If you’ve verified this is not the case in your situation, could you provide a bit more clarification on your setup? Perhaps the view.json file along with the value you searched for?
I WAS able to replicate the search issue with the Vision Extension Function. I’ll open a ticket for that right now.
UPDATE: There is already a known bug around find/replace in extension functions. It has been open since 2016. 
I noticed this within the Historical Playback exchange project. The logic making the magic happen in that project is a change script on the “tick” custom property. I found my searches are not getting results from that script.
Edit: I did test a custom property on a component and it worked. The issue is a custom property on the view.
Ah, thank you for the clarification. I do indeed see that those custom property scripts are not returning hits for expected values, which is especially weird because it dos actually scan the property value.
UPDATE: I’ve opened a new ticket to address the Perspective occurrence of this issue.
Hello,
Any update on these bugs ?
Quite hard to do some cleanup in scripts when we can't rely on Find not looking into the Component scripting of the power tables for example 
Thanks
No update. I'll note that it's still impacting users.