A lot depends on the individual situation, from my experience. When I first went to a rollercam, I didn't know any better and ran without a button. No problems. I WAS LUCKY
The next motor needed one, and It didn't require a lot of effort to keep all the parts happy. I sold that good shortblock, (bad move) and built a mega block motor. That one has so much forward thrust, it pushed a reenforced cover out of shape so far it was .010 from crashing into the adjoining lobes! I put a milodon geardrive on it to give it a very stiff thrust setup, and it started to eat the surfaces so bad I now have it drilled and tapped for a direct oil feed through the cover to the button. That provides enough lube so it hasn't eaten the parts anymore than it had. No one can explain to me why this motor does this. It has bushed lifter bores, which should eliminate problems, I would think. So, I am all in favor of using a thrust button. For a test just pull the distributor, crank the motor for quite a few revolutions with the valve train in place and see what it does.
If it moves the cam forward at all, better figure out how to address that. You want zero movement, or very close to it. Especially if you run a stock type distributor, no crank trigger.