Yes, finally Apple answered and sadly said NO :(. I have been sending and receiving several mails to and from Apple these days, but finally I think I have to surrender :(.
This is the exact last answer:
Processor state and low level system functionality is the domain of the operating system and should not be under user control.
Users who wish to use your product can still do so by booting into OS X’s Recovery OS and issuing one command, as detailed in the System Integrity Protection Guide.
Yes! It speaks by itself. I really never thought that Apple would deny the signature. I told them the app has thousands of users (the free version does :), but that seemed to make no effect. So… what to do next? These are the options and the next steps:
1.- If you really don’t want to mess with the system integrity features and continue using TBS normally, just don’t upgrade to El Capitan.
2.- Next version will include a feature to check the system integrity status calling the command provided by Apple, and instructions in order to disable it.
Please, give me your feedback about your experience on disabling the system integrity features if you’re currently trying it.
And…if you have another ideas, I’m all ears! Just comment out in this blog… :D, but for now, that will be the path to follow. I’ve sent a last appeal to Apple, but I really don’t have hope about they’re just considering it.