Is there a word for someone who works on a particular task without worrying about the time that he spends on it. Someone with an attitude of "it'll take as much time that it has to take". But he is persistent with the work, but doesn't like the idea of timelines.
That person sounds very lassiez-faire
a philosophy or practice characterized by a usually deliberate abstention from direction or interference especially with individual freedom of choice and action
or perhaps prefers to work unstructured
not happening according to a plan : not organized or planned in a formal way
I suggest a close adjective.
That someone is unbound.
not controlled, limited or influenced by something.
The person sounds like 'a plodder'
A person who plods, esp one who works in a slow and persevering but uninspired manner