Pushrod selection

That should answer the question.

I think most people expect the tension from the lifter on the valvetrain to be tighter than what it really is.

After the motor is shut down and the internal pressure in the lifter normalizes....... any rocker you check that has the lifter sitting on the base circle will have only the tension from the tiny spring under the plunger...... that’s it.
The rockers will easily slide back and forth on the shaft.