Again, a picture of this portion of the plans would aid us in better understanding if the strip is for aerodynamic reasons or simply to stiffen the flat wing.

All in all if the strip extends out in front of the leading edge I'd say that the reason it's there is aerodynamic. If it rounds up and back it's likely more to stiffen and ensure the wood stays flat. In the second case it SHOULD be OK to move it to the underside.

The other option is to build as per plans, try it, then cut it away and try it on the bottom. Use basic carpenter's "yellow" glue and glue a strip of printer paper between the wing and the stiffener. This will hold well enough for flying. But later on you can easily wedge a knife blade into the paper and split away the stiffener to leave have the paper on the wing and half on the stiffener with essentially zero damage to the wood of either part. Then glue it on with the same system to the bottom and try it that way.

Assuming you're using iron on film as a covering it's a snap to leave slots in the covering for gluing on the stiffener and then iron on a patch stripe to cover the side with no stiffener.