When you have a lot of mods installed in a specific load order and you wish to try testing a new mod by itself, it can be a pain to go through and add all the other mods again, and manually adjust the load order in the Skyrim launcher.

I recently realized that instead of doing this through the launcher, I can simply edit plugins.txt and even keep backup copies of the plugins.txt file with various mod load order profiles, which seems tremendously convenient.

Is there any potential drawback to using this method instead of the launcher?

just the usual stuff, duplicate entries,spelling errors, and misplaced esm's can cause serious problems, but other than those its a very efficient way to quickly test stuff out.

I would use BOSS to create your "default" plugins.txt and adjust from there.

I have a separate character profile in Bash that I use specifically for testing. Obv I wouldn't be testing mods on existing characters, but it makes it easy to switch between an empty load order and my real characters.