Retirement tax questions

Oh, and by "you must track each conversion separately" do you mean the year (so 1099-R) or each little conversion made within the year (cash $xxxx.xx on 4/15/2024, stock XYZ 10 shares @ $xxx.xx on 7/31/2024, etc,)?  I can download my transaction history for all "journaled" funds and shares since I've been with this brokerage (2020), I don't know how long they will keep those available.  I have most of my paper records from 1999 (I think that was the only time I converted anything, the rest of the Roth was contributions starting in 1999) but may not have all, and I've sold most of the mutual funds and stocks that were converted at that time, and invested the money in other things - do I need to be able to track the dividends, capital gains, and stock splits on all of my original stocks converted from my traditional IRA in 1999?  I'm afraid that will be an impossible task.  I thought you didn't need to track basis in a Roth?