Extremely bad idea, demonstrated over the past several generations. The LIbertarian Party started out with that in mind, but ultimately became the captive of tinpot tyrant radical activists, and degenerated into a small puddle full of internecine power struggles. Ross Perot helped to split the conservative vote and enabled Bill Clinton to become President.

Right now, MAGA has preeminence in the GOP and the objective should be to coax (or force) out the RINO component. Let them form a third party and split the globalist vote. If we can't do that when we have the upper hand, we have no hope of establishing a third party anyway.

It never fails in politics. The amateurs don't want to finish the job ("Kill the RINOs!") because it would be hard work, so they think they can avoid the problem by starting all over again new. Rather than fix the roof on their house, they would prefer to tear it down and start all over fresh?