i cant comment on the mtx4 gearing its self coz i dont run one, but for the basics ill give you an example, 1st gear pinions 16t, 17t, 18t, 1st gear spur gear 58t, 59t, 60t. the combination that will give least top speed/best accelaration would be 16t pinion 60t spur, slightly more top speed you come down a tooth on your spur to 59t, then 58t, after that generally you would fit a 17t pinion and back to a 60t
best top speed/ least accelaration would be 18t 58t spur.

then obvously same again for 2nd gear.

is this what your after?