Adding a third running board support

Hi, my 2021 PB XLT has a provision to add a third running board support bracket. The unused bolts for this bracket are at approximately the b-pillar. I have had no issues with only the two support brackets, but I do feel some give when stepping on the running board getting into my truck.

So, is this a waste of time or a prudent addition? If you have added this bracket, any advice or gotchas I need to lookout for? The brackets are $35 a pair on eBay so the cost is minimal.

Thanks.