Before
It is likely occur a sink mark at the thicker section same as plastic injection moulding.
The sink mark leads crack during sintering process. Also the raw material cost is high in MIM, thus larger volume leads higher unit price.
After
If the thick design is necessary, hollow out from the possible side. These hollows will help to avoid the sink mark or void. Also it helps minimise the unit price.
Thinner is better in MIM.