I don’t think Pence supporting Trump helps Trump. Pence can say whatever he wants but he pulls zero weight. I doubt Trump would invite Pence to any events and definitely not to speak.
Do you think he would get a speaking slot at the nominating convention if the contest by then had already been won by Trump?
Dude was VPOTUS and all...for four whole years before he took the 30 pieces of silver.
Pence can support Trump by refusing to support him.