The 8511 is not a good choice if you prefer not to double mask.
It will protect you, but it will not protect people nearby to you.
Here’s my opinion. Retail masks (including ‘surgical’) will catch a low percentage of the particles that the virus rides on. The mask is there to stop the particles from traveling forward and away from the person talking/breathing by greatly reducing the distance before it hits the ground. Hence, the 6 feet. Also you don’t get sick or get infected unless there is a high virial load. Most masks leaks at the edges where the mask meets the face and ‘vents’ vertical or back. The cloth/stretchy ones that I have been able to examine may have tighter edge fit but due to the stretch of the fabric, actually just vents through the ‘pores’ of the fabric, multiple layers help this.
I find the best for daily use (i.e. shopping, out and about and are ‘somewhat’ social distanced) are masks which have a hard/formed surface with multiple compressed layers, like sanding masks (https://www.woodfinishersdepot.com/images/A3%20Sanding%20Mask.jpg). These fit the contour of your face fairly well and much better than the blue surgical masks. Additionally, because of the extra surface, it makes it easy to breath, whereas, the surgical are right up against your nose, hence less surface and harder to breather … comparatively.
Finally, while particles with the virus does come from from the nose, it’s the mouth, especially when being vocal is where the danger comes from due to the velocity of the particles being ejected away from the source.
I am not a doctor, nor do I play one on TV. I am not a scientist, … well, actually, I am but not the type of scientist that has anything to do with biology so I’ve made educated guesses from what I’ve read online… which is another issue (reading stuff online from unknown sources).