OK I have some images across in IMatch and the XMP IS working - my keywords are there - yay!
In iMatch V3.6 you may find that want your keywords in a different place, such as IPTC Keywords or iMatch categories. If you decide that you do, then we should be able to help you out.
Aftershot should be ok as a RAW converter when the next release comes out, but I sure wouldn't want to use it as a DAM.
F_P