Are robots allowed to cross the same defense twice during autonomous, and get points both ways?
Points are only awarded for the first CROSSING during autonomous.
See section 3.1.3 of the manual:
Once a ROBOT CROSSES a DEFENSE in AUTO, any additional REACHES or CROSSES by
that ROBOT during the AUTO period will not decrease DEFENSE STRENGTH nor contribute points to the
ALLIANCE
Also (in addition to what lopsided98 said), keep in mind that what you’re asking (“get points both ways”) likely indicates a misunderstanding of what a CROSSING is. A CROSSING is only valid one way - i.e. from the NEUTRAL ZONE to the opposing COURTYARD.
See section 3.1.3 again:
A DEFENSE is CROSSED by a ROBOT when that ROBOT
■ starts free of contact with the DEFENSE and completely in the NEUTRAL ZONE
■ traverses the DEFENSE such that its BUMPERS go fully between the adjacent SHIELDS/GUARDRAIL, and
■ ends up fully contained by the opponent’s COURTYARD.