I like the idea of informal vs. unmarked but in practical terms the difference is not very significant.  The connector was apparently added to improve pedestrian navigation here.  Since the crossing node and way are both properly tagged as "unmarked" I think it’s fine and can be left as it is.

(I think it’s time we file another bug report to StreetComplete devs because it’s not the first time SC users do not notice the difference between normal crossings and unmarked ones.)