I'm wondering if what they have built so far is not actually the new pedestrian crossing mentioned on the notices, but an access point to allow Road-Rail vehicles to get on and off the tracks?
The old pedestrian crossing is still in use and there is no sign of a new path across Shepherd Meadows, just the old gravel track dotted with puddles.
You're right. The Darby Green level crossing is at LOR SW265 56m 22ch, and looking in the EAS, from March there are two entries near there marked "
RRAP▸ work 56m 14ch and 56m 30ch W2020/7423979". Which says much the same thing in railway-code.
Why there are two sites, 320 m apart, I've no idea, unless it's really defining a stretch of line. Where is this new access gate? I'd expect it at the end of a cul-de-sac, of which there are several along there, but none lines up exactly with that LOR chainage.