No disagreement here (@abgd, SSD, GtW), but I maintain that compared to the "mind-sharpening" experiences from planning and conducting GA flights which SSD mentioned before, enhanced VFR aerobatic skills and tailwheel experience are rather low on the must/should have-list for being proficient in the airline environment.
Put differently, I would probably feel somewhat uneasy as SLF with a cockpit crew who have hardly done any actual "raw" flying. But I wouldn't care at all whether this flying was partly inverted or which side the auxiliary wheel was on.