Now that was WEIRD. On my 2nd try this afternoon I jumped at the tunnel and it appeared I was wide right and bound to fall back to Relto. I never entered the tunnel at all but when the linking was finished, I was in the Bahro cave! Not wishing to overthink my good fortune, I grabbed the Bahro wedges and let myself fall into the stars...
Now to rinse and repeat for my 2nd avvie.
Got the 2nd avvie on the first try... what strange magic is this? This time I was in the tunnel but had jumped so far I immediately went thru the trigger point for the link.