Johnson and Weld are no libertarians.
Their only function is to throw sand in Trump’s gears. If Johnson was to appear onstage, he and Witch would tag-team up against Trump
Personally, they might get more of the potential Witch-vote than the Trump-vote.
I can't see how true Libertarians can endorsed these two - they are for taxpayer funding of abortion and for more restrictive gun laws.
Neither of those are "neutral" stances.