In "Changelog assistants" file I see, that ESS now suppports limitting FeedIn power:
Release date: January 24, 2020
Supports limiting the FeedIn power. (Starting from firmware revision 469)
I updated my MultiPlus 48/5000/70-100 to 2624469 firmware version, but I cannot find in ESS menu on CCGX panel the line, in which I could limit the FeedIn Power.
Maybe it does not work because I have 2 Multiplus devices in parallel?
What I have also found out, that though I disabled FeedIn, it still feeds energy in, taking it not only from my Solar panels, but also from my batteries. Isn't it strange?