Kdo. Braunegg and NAG 6 did all their Me 262 conversion training at Lechfeld but left when they became operational. By 27 March 1945 the Stab, 1. and 2. Staffeln were at Vörden, Ahlhorn and Münster-Handorf. 1./NAG 1 had also converted in Lechfeld but was operational from Zerbst on 6 April with all its serviceable aircraft.
On 8 April 1945, Maj. Kröchel at Lechfeld advised Luftflotte Reich that "Re-equipping detachment Close Recce" was at present training 8 pilots of 1./NAG 1 on a SILBER [Me 262] borrowed from III./JG 2 [sic]. I doubt if they'd have to have borrowed an Me 262 from III./EJG 2 if there were aircraft of their own at Lechfeld.
The Americans arrived in Lechfeld on 27 April, as near as I can tell.
There are
two articles about these Me 262 reconnaissance units on my website.