Selling stocks and filing taxes

Hi everyone,

I’m fairly new to investing and trading and I’m not fully sure how to present this question.

My Dad has told me a story about when he first started investing in the early 90’s and made a mistake that caused him to have a massive headache when he did his own taxes at the end of that first year.

He had decided to try day trading, and had bought and sold several thousand shares of various stocks throughout his first year. He said that when it was all said and done, many of his sell orders went through at various dollar amounts, causing him to have a massive and unexpected headache at the end of the year where he sold x amount of shares at x amount of dollars and then another amount of shares at a different x amount of dollars and so on and so forth. He said in order to avoid this headache again, he always sets his sell orders as “fill or kill”
But, as I said, he does not do his own taxes anymore.

So my question is, does setting sell orders as “Fill or Kill” make taxes easier at the end of the year, or does it all come out the same on a 1099?

All the stocks I am currently invested in are OTC and may not be so easy to sell with a fill or kill order, but my biggest fear is creating a major tax headache for myself down the road.

Thanks for any input and advice!