To paraphrase Yoda, Type or type not. There is no backspace.
The backspace key is addictive. Once you start backspacing, you can't stop. You'll have to fix all of it. The typos. The dangling participles. The disappearing, reappearing, re-disappearing characters. The settings that magically change from the beginning of the sentence to the end of the sentence. The nauseatingly flowery descriptions. The forbidden adverbs. The bad dialogue. The messed-up line spacing. The plain old bad writing.
Do. Not. Backspace. No matter what. To paraphrase Monty Python, the backspace key is no more. It is an ex-backspace key. At least until December first, at which point you'll have 50,000 misspelled, ill-used adverbs of completed first draft to revise.
In other words, don't backspace until after you've written a novel.