Using an alternate foundry constraint for DRD Edit / overwriting minSpacing values from foundry constraint

Hello,

I'm trying to use DRD Edit tool with different spacing values than those found in the foundry constraint.

In the documentation it is mentioned that in order to do this I simply need to have another existing constraint and load the following env var in .cdsenv:

cdba.layout AlternateFoundryCG string "AFCG_name"

I used this and confirmed that the env var previously mentioned is indeed loaded. But after multiple attempts to get this to work, I cannot get the tool to use an alternate constraint. I've tried multiple types of names ("foundry_test", "AFCG_foundry" "AFCG_test" etc) for the alternate constraint, having unique rules in its spacingTables so there isn't an overwrite issue and even removing the foundry constraint data altogether. The tool does not change constraint, it always uses foundry.

Am I missing a step?
Is there perhaps any other way to overwrite in DRD Edit, for example, a minSpacing that is found in the foundry constraint with another value?

Thank you,
Mihai