Sure;
Every modification has an effect(s).
Internal wing stores have many of the same, as in position of added mass, changes in structural stiffness etc.
That's not a prohibited thing, it's something to be aware of.
Flying with additional payload, of external stores will change the characteristics of the A/C, thus the mission. The aircombat movies always start the grand melee with "Drop Tanks!!". With that, the plane is converted from a long range aircraft to a combat aircraft.
I this case, tanks change a sport aeobatic RV-8 to a long range cross country cruiser, or pods could carry Christmas gifts for grand children.
No whifferdills with these attached.
Flight testing required.
Why do we build aircraft anyway???