Apologies for the delay in responding. Was out for a few days.
I don’t think the KE4 MAX #4 iron will give you more trajectory. It actually is 1 deg. stronger lofted than the TS2 #4 iron and the vertical CG is not enough different to make a difference in the trajectory. Yu do need a 20 or 21 deg. lofted club, it appears, to get the distance gap you need, but will also launch it higher than the #4 iron(s). I would look at either the STh2 #4 hybrid (MA0316) which is 21 degrees, or the M890 H3 Hybrid (MA0320) which is also 21 degrees loft. Both are 240 grams in head weight and depending on which shaft you want to use, should be able to be built to a length that would blend in with the iron set. Depending on the length of your irons, it would probably need to be 3/4″ to 1″ longer than the 5 iron. Should give you the trajectory improvement and also fit the distance gap need.
Another possibility could be the FDI #3 iron/hybrid, but I don’t think you will hit it as high as the two suggestions above. You may hit it slightly higher than the MAX #4 and the TS2 #4 simply because it has a lower profile and slightly lower vertical cg, but I just don’t believe it would be a dramatic difference. I have the #3 and the #4 in the FDI replacing the #3 and #4 in my TS1 set and I love them. I do hit them slightly higher than the TS1 #3 and #4 irons, and they are easier to hit (more forgiving).
So, the STh2 and the M890 hybrids should give you the most notable difference in trajectory. The FDI might give you some difference, and should be slightly better than the TS2 #4 or the MAX #4.
Hope this helps.