If you are using base-flange, then you cannot generally pattern your
sheet metal specific features.
But if you are using insert-bends, you can accomplish this with ease by
patterning "pre-bend" insertion (roll back before sheet metal).
Additionally, if your pattern is linear and all the resulting bend
panels are planar, you could combine them into a single sketch yielding
Regardless, you may not pattern any sheet-metal specific feature in
either modeling mode. Personally, I prefer the insert-bends mode for
the more open modeling techniques. The base-flange is a bit weak and
there are some techniques that are prohibited. Much like boxing with
one hand tied behind your back.
If you can post a model, maybe we all could give some advice.
In any case, best wishes.