This tool sets the handbrakes for all cockpits, remote control blocks, and control or flight seats. It does not toggle anything else that would normally be affected by pressing P.
Paste your sandbox_0_0_0_.sbs (not your sandbox.sbc file!!) contents here:
Your modified sandbox_0_0_0_.sbs file:
Remember to delete the caching file sandbox_0_0_0_.sbsB5 before launching or it will take precedence over the SBS file!
Deleting the SBSB5 file will cause SE to complain that "the file format is outdated". This is expected and shouldn't be a problem.