I've tried to create some monsters and there are improvements that could be done, here some suggestions.

1. Please put the class fields like in the standard monster stat block, enter Features, actions and reactions before the stats is counter-intuitive.
2. Hit points: hit point die value and hit point modifier have to be entered manually, why ? You can calculate them automatically using the size, entered hit point count and constitution modifier.
3. Weapons: If I want to create a variant of an acolyte for example with a different weapon, I have to manually change the text and calculate the values, why not do it like in the character creation and be able to add and remove weapon, armor, magic items using the actual weapon and armor from character creation.
4. Race: If I want an Azer acolyte, again I have to do the work manually, we should be able to add the race Azer to the acolyte.
5. Classes: If I want a boss monster and want to add x level of sorcerer class to a yuan-ti.
6. Traits: A lot of monsters have common trait, why not have the traits separate so we can simply select them instead of the need to put them manually as text.
7. Skills: Currently you have to enter manually the skills and there values, but again, the values can be calculated with the stats, why should we enter them and calculate them our- self, this is prone to errors.
8. Race sub: Currently, I can choose Humanoid type, but in stat-blocks you usually have a sub-type under parenthesis, ex: Medium humanoid (yuan-ti), ...