I'm confused. Looks to me like that set of instructions is carried out in LR. What is SNS? Where does one get it? What makes it different and better than LR or PS for masking? How does one actually use it in comparison with how one uses brushes in LR and PS for the same purpose? Grateful if you could explain the context a bit.
In addition to Erik's response, SNS-HDR
is (arguably) the best (HDR) tonemapping application available (for Windows, although it apparently runs fine under Parallels and the like on a Mac). Even though the LR/ACR's PV2012 tonemapping has closed some of the gap, SNS-HDR still offers a feature set that's hard to find anywhere else. It also reads .EXR files, the most universal HDR fileformat for photography related scenes.
Especially when dealing with 'impossible' scenarios, like shooting straight into the sun or when shooting interiors with a brightly lit outside view, the only solution is to shoot multiple exposures, which SNS-HDR handles gracefully. LR would require a roundtrip to Photoshop to create a huge HDR TIFF, where SNS-HDR just takes the individual exposures and interactively or in batch produces very natural looking output.
What Erik wanted to highlight is that the application also can work miracles on a single file, although it's limited by what the image has to offer (e.g. noisy shadows or blown highlights). There the difference with e.g. LR's PV2012 becomes smaller, although SNS-HDR offers special tonemapping features not found in LR and its realtime updating preview makes for a very creative and interactive use of the controls.
P.S. I've added an example of tonemapping of an HDR scene detail, where I've tried to match the look of the LR tonemapping (but without the posterization artifacts)