If you don’t have the rails, you could sit it on top of a shelf, but it would be really unstable. These things are too heavy to support just from the front, hence the rail kit.
this is what i might do, the v2 is real short so i might feel alright putting it on a shelf, it would be a shelf designed to hold servers where it has supports in the middle regardless
There are rack shelves designed for this, I have been to production DCs that had rows and rows of servers on shelves. Just check the weight ratings. These servers are not designed to be mounted by their ears like switches. The proper rails or shelf is the solution here.