I use servo match on my DX18. It has 7 way points along the travel that you can sync with. BUT, bear in mind in can only be as accurate as the linkage is tight. You still have to get the mechanical adjustments as close as possible first. There will still always be some variance due to linkage slop and general differences between the engines. Just to clarify, we're talking 4 engines here. When I loose one engine, I just lean a little on the rudder with a bit of aileron.
Edwin