we are in the progress of migrating freeradius servers and encountering behavior changes

1.X: "check_item := takes precedence over group check_item :="
2.X: "check_item := being overwritten by group check_item :="

current_release=1.1.8

target_release=2.2.3 (or any other stable)

Some more detail:
sqlcounter.conf configured with:

sqlcounter limitvolume {
                counter-name = Octets-Total
                check-name = Max-Octets
...
}

behavior for:
Max-Octets with operator ":="
ONLY groupcheck item set

result in 1.1.8: groupcheck-item is taken,  no issue

result in 2.2.3: groupcheck-item is taken,  no issue

result in 2.2.3: groupcheck-item overwrites usercheck-item, user not able to increase his volume limit independent of the group he is a member off.

I've validated as well in 2.1.12 which yields the same behavior as 2.2.3.

So behavior has changed from 1.x to 2.x

How can I make a user inherit group items while still overriding specific user check control items.

The of "=" is not allowed, so i'm currently without direction in how to get this behavior back. Is this a bug or intended behavior, and how can I resolve this?