Clean code is code you and others can understand and everybody seems to have a different idea of that. Sentence long variable names I don't like, they slow me down when thinking about or remembering what to do I'm not sure you can remember the names without Intellisense/IntelliJ autocomplete. I don't think I would enjoy working on this codebase.
The recommendation I read back in the 90's in Code Complete that has served me well ever since was that variable name length should be roughly proportional to the variable span. "Variable span" being the distance between where the variable is first defined and its last use. Generally that means that a temp variable inside a short function can be a single letter since you can see the full context of its entire lifecyc…
One anecdote I remember from the book, is how for a while Excel allowed for dual colored cells based on a parsing error due to trying to be too clever.