[Xymon] XymonD --merge-clientlocal issues

We have set up a new 4.3.28 xymon server, and will be migrating hosts to it in the next few weeks. On it I would like to start to use the --merge-clientlocal command. In testing, Windows powershell clients pick up either the individual host section OR the powershell section, it does not merge. Are there subtleties not in the man-pages that people have found to get it to work? (note that the xymond man-page states to use --merge-clientconfig, but that doesn't work either)

Could it be the section/host headings, or order? I have:

[server1] file:somefile

[server2] file:different file

[os=powershell] (also tried [class=powershell] and [powershell] alone) xymonlogsend clientversion:2.28:http://url

Thanks, Tim Williams