The short answer is yes; I've seen it done well, and I've seen it done poorly.

In the "done well" department the mess jacket had been ordered from Marlow-White (www.marlowwhite.com) with the branch of service facings on the lapels chosen to compliment the kilt (for those not in the know, each branch of service in the army has a specific colour: sky blue for infantry, red for artillery, gold for cavalry, etc.). Absolutely no military trim appeared on the jacket and, because it had been made to measure by Marlow-White, the fit was excellent. The down side to all of this is cost-- military uniforming isn't cheap, and for about the same money one could probably buy a well-made coatee or doublet.

Done poorly? -- I've seen men show up at Highland games in second hand mess jackets that were sizes waay too big, complete with insignia of rank and shoulder knots. Not a pretty sight.

Done right, a mess jacket makes an excellent alternative to a doublet or coatee, and the "summer white" mess jackets worn by all branches of the US forces can be very comfortable when the temperatures rise. The Army's blue mess jackets are just that-- blue-- and may not look their best when paired with some tartans; the Navy's blue mess jackets are a deep, inky, blue-black colour, and are probably a better choice for conversion.