It is not an endorsement of anything but a person’s right to choice and a right to vote for who they want, to argue their piece as a Candidate, so signing nomination papers endorses no position. Saying “I endorse ______ and their hashtag” is an endorsement. Or letter to editors and statements to the press.
Signing isn’t a vote or statement of anything more than all even the person running has a right to choose who they want to vote for, and man even having to collect 25 voters from those presumably able to vote is a lot for me to be able to vote for who I want to (really if I am not going to vote for myself, I have no business running).