this works in our instalation. Under plugin.tx_solr.index.queue pages, the fields "url", add code to inside default "pages" configuration:
..
fields {
url = TEXT
url {
typolink.parameter.field = uid
typolink.returnLast = url
typolink.forceAbsoluteUrl = 1
}
sortSubTitle_stringS = subtitle
}
..
pages are then searchable across domains.