Fist of all, thank you for your contribution and your time.
... it is important to refer to the API Docs... For example, the docs with the LoadupMonitorProxy class.
I could not miss the API page about LoadupMonitorProxy that I fully translated http://www.daigleetcie.com/loadup/LoadupMonitorProxy.pdf (I am about to recitate it like the rosary

Also I can hardly do without sample that I patiently try to understand ( that's the way we learn isn't it ?)
In case of LAO, believe me, I was not the only one to wonder why some loadings were failing. Thank's to Tek, I could reconsiders this sample as "a demonstration how the application react when there is failures" and discovered that business layer was in fact ramdomizing routines (...if only these Invoice, SaleOfOrder or DebitorAccount could have been xml files, it would already be done

In case of LFA, you seems not considering your demo reliable enough for real application ( of course, we surely have not the same level of mastery). I don't agree and since then, I desperately try to replace the monitor I used, based on StartupMonitor proxy (included in AppSkeleton demo) by a LoadupMonitor instance. The former one was working just fine but loading up resources whenever needed and not just during startup phase is really interesting,indeed.
LFA nearly seems to answer my needs (i.e load and exploit in an ordered way some xml configuration files)
The only difference I see is about the view layer that is, in my case, no more required. So I believe I can delete GroupOfAssets.mxml and its mediator but if as you suggest, I delete all others files, what should I replace it by ? Where should go all business code from the GroupOfAssetsMediator, LoadAssetGroupInstructions.as LoadAssetGroupCommand ?