As you move the stem up the bars are going to move towards you....It sounds like you got a double whammy with the stem length when you changed to a Technomic... You brought up the Bars which also brought them closer to you, and you lost 4cm off your stem....thats a pretty big change when you add those together...no doubt more than 4cm of reach was lost.

It seems like you already know what will help... move the seat forward and get a stem that's of similar height but longer. If you bought your Nitto Technomic from a decent shop they should let you exchange it for 100 or 110.