You are reffering to the Stuka D. This one did indeed saw combat in north africa and Eastfront.
However, we are talking about typical bomb loads. A stuka could carry 1 500KG bomb and 2 250 KG bombs but this was very rarely carried. A typical JU 87 C or D often carried one 500KG and 4 50KG. As the 50KG bombs where VERY usefull in attacking truck convoys.
But there are some other changes. For example the armor was slightly increased and a New dual barrel MG81Z was installed in the rear gunner.
I say support the proper allied ground attack aircraft aswel, and it gets my blessing
As for the ME109 with 250KG bombs...this could be done, but it was rarely done...