Some tenets drive people to a religious
crab-pot mentality.
If Luther did not dissent, there would have been no Reformation.
If the Anababtists did not dissent, there would have been no Believer's Baptism.
If the principals of the Welsh Revival did not dissent (about not quenching the Spirit), it and subsequent revivals (like Azusa Street) would have been stifled.
Which of those progressions is worth giving up in the name of "unity?"
Does the fact that some refused to make said jumps make them heretical?
There are certainly heresies to avoid, but in my experience when God brings new revelation --and He must in order to fulfill 1 John 3:2-- some will move forward and others will not.
If the latter maintain the basics, they will still be Saved. They will just plateau in their growth unless/until they change their mind.