This is an ever/never issue.
Please check out the transformations one can make while keeping the same basic meanings.
- before ever doing something:
ever is indirectly related to never. Both are adverbs
The second one can be contrasted with: never doing something
- Before I ever do any work, I try to have fun.
- I never do any work before I try to have fun.
"Before ever writing Chapter One, he will etc."
is the same as:
"He will never write Chapter One before he does [whatever]
That should help you understand ever, the adverb.
The adverb ever can be used like this regardless of tense.
- Before ever studying at university, he played professional soccer.
- He never studied at university before playing professional soccer.
The point my answer is making is the transformation of: Before ever + verbING or verb phrase into subject + verb + never + before +verbING.
Before ever giving the dog a bath, I clean the house.
I never give the dog a bath before I clean the house. [a general statement]
It's easier to grasp using never/ever in the simple present as a general statement about something. That is basic usage that ELLers usually learn in a first-year English course, along with the other common adverbs of frequency: sometimes and always. Of course, there are many more as well.
Ever and never are related to each other:
- Do you ever go out after dark?
- No, I never go out after dark?