Thank you Victor, this clarifies things for me. Interestingly, I could not find any reference to a v2.21 switch-over to Lagrangian strain for deformation plasticity outputs. The Table 18 entry describing the output variable E as Lagrangian strain appears to have remained unchaged since a while ago (I traced it back to the manual for v2.17).
The most relevant record I found was Guido’s plan to switch the strain output from Eulerian to logarithmic strain in the following post, which coincides with v2.21 release period. Perhaps Guido decided to use Lagrangian after that discussion:
Either way, good to know this detail.