I have a question about how Nen works

I haven't watched it in a while and haven't looked into HxH, but I had a question: What if a Nen user (transformer type) is talented enough to create multiple Nen abilities and switch between them during combat? (I don't remember the process by which a user creates their Nen or if they can switch it after creating it, so I was wondering if someone inhumanly talented could create a Nen ability, overpower, create another one, and also overpower it, and thus be able to switch Nen abilities during a fight.)

Not as an ability with several functions, but rather inventing Nen abilities with different characteristics and functions and being able to change them during combat (an example that occurred to me is as if a Zoldyck with transforming Nen decided to take advantage of his resistance to poison and electricity to create 2 different abilities to get the most out of both and be able to change abilities during combat)

In short, it's like a very talented transformed user wants to use several Nen abilities without having to have multiple conditions or being weakened and decides to create Nen abilities and change abilities during the fight, although what I really don't know is how long it would take a Nen user to change abilities: seconds, minutes, hours?