Hello! First off - I am a huge fan of TotalSpaces. It has dramatically increased my productivity both at work and otherwise.
I have been using High Sierra at work as that is the last version of macOS that supports running TotalSpaces with SIP fully enabled (after the installation procedure). My work has a strict security policy and disabling SIP is a no-go. Unfortunately, High Sierra will soon be unsupported by Apple and I’ll be forced to upgrade to Mojave or Catalina. When that time comes, I will be unable to use TotalSpaces.
Have you considered making a signed kernel extension that implements the functionality of TotalSpaces? If it’s any motivation, I would gladly pay for a new version of TotalSpaces that works with SIP.