I own a hose shop. Not only would I not guarantee it, I wouldn't crimp it either. Do you bring eggs to a diner and ask them to cook them for you? If you want to save money, buy a hose crimper and crimp them yourself.
Now the big thing is the safety factor. Everybody makes a 100R2 hose which all have identical specs. However, there are huge differences between the inner and outer covers. You can crimp one brand on another successfully. And, you can crimp one brand on another and have the hose pull out of the crimp and kill you.
I may take some flack for this but I don't care. You try owning a business and have someone buy something somewhere else and ask you to make the final product on your thousands of dollars of equipment then when something goes wrong he wants to sue you for everything you have. And of course, because you really didn't do anything but crimp it, they don't think they should have to pay you a nickel for anything.
You can buy off the internet all you want. Where you gonna go when you have a problem? They employ phone temps for 8 bucks an hour. Try getting someone after 5 pm. Now try a Saturday? Ha! This is a big reason I have slowed down on posting here. Sure, there are a lot of hose shops out there that rip people off, but please don't paint with such a broad brush. Sorry for my rant but I have spent hundreds of hours giving advice here. Notice the only time you see the DHH guy is when he is giving his own company a shameless plug. I will put my knowledge and product quality against any internet hose seller out there. In business, you have 3 qualities. Speed, price, and quality. You can only have 2 of the three, this is a fact. You make the choice.
Andy