I am setting up the work hours functionality and i have one question and one suggestion.

I can not set as mandatory the field and i can not do it not even in the blueprint. Is there any way to validate this field or is something out of standard fields?

i checked a workaround via a custom field formula saying if work hours < 0.01 return 'work field is empty'. 

I would then take the value and use it for validation in my blueprint but this solution hit a wall on the auto-population from Duration hours which brings the next problem.

The duration auto-populates Work hours (if not already the hours have given manually). That is a problem. Maybe an org setting saying if you want this to happen can be better. It totally destroys the calculations! You put 3 days for a task of 1 hour because you just want to put the period without set the work time estimation and you get a 24work hours in estimation. You can not set the field as mandatory or validate it and you have 300hours tasks that are 3 hours. better have zero estimation than have totally wrong estimation

We call it estimation because only someone who knows the job can estimate and definitely a bot can not. 

Besides those problems, the function is well designed and i love the 3 options Work hours per day Work % per day and Work hours and the the work load feature for the recources.