Ah! We got it!
/System/Library/ScriptingAdditions/TotalFinder.osax must not exist and
/System/Library/ScriptingAdditions/TotalFinderSIP.osax should exist.
I will have to review my code. I'm not sure how you got into this state.
Installer should remove that file when you are in SIP-disabled mode and install TotalFinderSIP.osax instead.
To fix your situation:
1. disable SIP in recovery OS
2. boot back into your main system, uninstall TotalFinder, this should remove
/System/Library/ScriptingAdditions/TotalFinder.osax, make sure it was the case
3. install TotalFinder 1.9.3 again from scratch
4. boot into recovery OS and enable SIP again
Details here: https://totalfinder.binaryage.com/sip
I'm sorry for this annoyance. I will have to figure out how anyone could get into this state.