I plan to add a bottom rail and a vertical grip....so I'm not worried about heat too much.
I checked the link... and... Out Of Stock. I'm glad the American People are waking up... finally... but crap... I'm getting tired of seeing Out Of Stock. Magpul has listed most items as Dealer Only. Spikes has a 12 month wait for BCGs and lowers.... And the rare one you do find for sale on the Internet is priced so high no one in their right mind would buy it. OK... enough ranting.
I have sold these forearms in the past and they are both great products. I don't think you would feel anything like a cheese grater unless the metal was chipped somewhere. Was there some parts that you were looking for? I am in the process of rebuilding my online store but i can give you quotes on products. Unlike other companies I like to help the people so I keep my prices low. Usually at least 7% below MSRP. If you need to know anything about AR-15 parts let me know.