Edit nested udt parameter - Ignition 7.9.10

Hi, so I have a script to import PLC channels addresses (stored in a db) into nested udts parameters. For that I use the system.tag.editTag scripting function.
I manage to get this working in Ignition 7.9.7 by putting the nested udt name in the parameters dictionary key (http://forum.inductiveautomation.com/t/tag-edittag-sub-udt-parameter/18768). But the editTag function doesnt seems to work in this version.

Here’s an simple example of what I’m trying to do:

udtTag = 'LZ System Test/LN2 Dewar/Valves/6000SV'
childName = 'Valve On Write'
opc_path = 'aPath'
system.tag.editTag(tagPath=udtTag, parameters={childName+"/opc_path":opc_path})

FYI: 6000SV is a UDT of the type “Valve” with a ‘Valve On Write’ UDT of the type “Control”
Is this a possible bug?