if you have to buy something very soon at HD,buy gift cards from third party gift card sites on discount and use them. I wouldn't keep unused GC bought from third party website for long. It maybe be way more better then using any cash backs or points/miles card at the store.
when we moved in a new condo, first purchase, we had like almost a dozen 10% off code from usps and also bought some for $1 on ebay.
We used those at lowes almost all and one at HD. When using Lowes coupons at HD store, DO NOT ASK THEM IF THEY ACCEPT IT OR NOT. Just go to the payment counter to pay and after scanning your products, show the lowes coupon and tell them it is a competitor lowes coupon and they will accept it.
I even bought cooking gas ranger online from HD after price matching from a different online store and also had the chat agent accept 10% lowes coupon.