Short answer — no. Do NOT cut/splice into the existing airbag wiring for any reason.
The TJ airbag module only knows about the driver & passenger dash airbags. It monitors those electrical circuits for a predetermined amount of current at all times. If you splice into those monitor/trigger lines in an attempt to add additional airbags, the airbag monitor would throw error codes and disable itself (and the TJ's existing airbags) entirely. At best, it throws no codes, but would very possibly not function properly in case of an accident. Pretty risky.