You have 2 things that can help you in a lake like that....sometimes with a thermocline the fish will not use deep cover in the summer, BUT, wood cover can attract certain types of algae that will give off oxygen...also in lakes that have huge expanses of weeds, they will keep the water highly oxygenated in summer allowing fish to stay deeper....In the winter, if the vegetation starts to die, it uses up oxygen and the fish will move deep again.
IMHO, you will be fine adding deep cover...it will come into play during different seasons, no matter what!