Does Lodge A-SPRAY provide any useful benefit over canola oil spray or bottled canola oil?
As you pointed out in your question, Lodge A-Spray is 100% canola oil. It is also in a non-aerosol container. Those two things mean that you have no added propellants or ingredients.

Most cooking sprays are not 100% oil. Most contain a additional ingredients, some of which would actually be a negative in trying to build your seasoning. Soy lecithin, for example, would create a quite tacky/sticky surface if allowed to build up. That would be quite the opposite of what you are trying to achieve.

As you note, there are many oils that work well in seasoning cast iron. Those sold in bottles work just as well as a 100% oil spray. And while typically the sprays are much more expensive, they are convenient.

Just remember that if you choose to use a spray, you always check the ingredient list to be sure it's 100% oil.