not sure, but probably
I am not sure which gap you are describing.
If it is the horizontal gap, between the main clam and the small panel directly behind the wheel, then the answer is yes.
In general, it is easy to move panels along the car. It is more difficult to move the panels away from or towards the mounting points, the car itself. The latter require adding or removing shims. It is possible to do this without removing the panels but is difficult because the location of the shims is difficult to reach.
As to moving panels along the car, such as increasing the gap, try this. Loosen the two bolts that attach the main clam to the panel. You can see them inside the wheel well after you remove the liners. The top portion of the lower panel is not mounted to the chassis but is sort of like a C spring. You can force the panel away from the body by hand pressure, increasing the gap, and tighten.
I do not remember exactly if I described it specifically, but you might read my front clam removal instructions for a better idea of where the mount points are:
Lotus Elise Maintenance, How to Remove the Front Clam
Michael