Windows ExtensionSettings registry key takes priority over ExtensionSettings REG_SZ/REG_MULTI_SZ

We are managing Firefox settings using Intune via Imported ADMX templates. We are managing Extension Settings via 'Extension Management (JSON on one line)' which works fine for our force installs, force removals etc. We have noticed that some users have installed 3rd party extensions which create the ExtensionSettings key in the registry with the 3rd party extension details. The issue we see if when ExtensionSettings exists as a REG_SZ or REG_MULTI_SZ under `HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Mozilla\Firefox` it is then ignored if the `HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Mozilla\Firefox\ExtensionSettings` key exists. Is there a setting we can use to have these settings merged by Firefox or have the REG_SZ/REG_MULTI_SZ take priority or is the only way to ensure enterprise policy continues to work we need to migrate our extension settings into the key rather than string? Thanks!