Not to prolong the agony, I tried the example on OSX for man tbl: .TS tab(@); ccc. This@is@centered Well,@this@also .TE
It didn't work with the nroff -man they supply. It did work with mandoc So my summary of understanding so far: FreeBSD: does not honour .fc no longer has functional tbl or nroff in base, does have mandoc which honours .TS/.TE OSX: does not honour .fc, no longer has functional tbl, nroff is braindead, does have mandoc which honours .TS/TE debian: has nroff and tbl. nroff appears to be groff. honours .fc. The minimal install does not have mandoc. apt install mandoc and it works.