So far linked proxies were just kept as-is, this is no longer an option. Attempt to convert them into liboverrides as much as possible, though some cases won't be supported: - Appending proxies is broken since a long time, so conversion will fail here as well. - When linking data, some cases will fail to convert properly. in particular, if the linked proxy object is not instanced in a scene (e.g. when linking a collection containing a proxy as an epty-instanced collection instead of a view-layer-instanced collection). NOTE: converion when linking/appending is done unconditionnaly, option to not convert on file load will be removed in next commit anyway. Part of T91671.