Hey @banjac90 you will need to make use of the include:
key in tmplates.yml
to override keys that already exist, but this may not make sense for your usecase.
See: Template.yml per-project includes - #7 by tannaz
To achieve your original goal, you can have similar definitions but different named templates.
asset_work_area_houdini_default:
definition: '@asset_root/work/houdini'
root_name: 'secondary'
asset_work_area_houdini_fx:
definition: '@asset_root_fx/work/houdini'
root_name: 'secondary'
Then any tk-apps or engines using these template names in configurations would need additional environment yml files configured with these values, and the pick_environment.py
hook (tk-core/hooks/pick_environment.py at master · shotgunsoftware/tk-core · GitHub ) would direct to the appropriate environment yml based on the context (ie. FX asset type).