yes the guidance to use 5498 is misleading, use year-end statements per Form 8606 Line 6 instructions
https://www.irs.gov/pub/irs-pdf/i8606.pdf
Line 6
Enter the total value of all your traditional IRAs as of
December 31, 2025, plus any outstanding rollovers. A
statement should be sent to you by January 31, 2026,
showing the value of each IRA on December 31, 2025.
