In my opinion it is not an exploit. Nothing that can be done using in game mechanics is an exploit. If you can figure it out, good for you. I remember when I figured out that I could go 100% chameleon in Oblivion. I purposefully avoided chameleon for the longest time because partial chameleon wasn't very useful. Then I had an idea. Pursued it and eventually after a lot of sigil stone harvesting, realized my goal. Triumphant!

If you read online and short cut your way to capitalizing on all the in game mechanics as fast as possible that is also your choice. But there appear to be people who do this and then only afterward lament not coming by it in a more normal discover it for yourself type of process.