Entire 59M would count on the 2026 cap; in that scenario the dead cap (79M) is already split : 20M in 2025 and the rest in 2026.
If 59M is too much dead cap to eat in 1 year I think we have 2 options :
1. He's our QB in 2026 as well and we stop restructuring his contract
2. Post june 1st designation in the 2026 offseason. For that to work we would need to carry his cap hit (currently 69M) until june 1st 2026 but I think we could potentially negotiate with him. Like, here's a 1M signing bonus, in exchange you drop your 40M base salary to 1M and you're now a free agent. That way we would carry his renegotiated cap hit of around 30M till june 1st, and after that it would be the dead cap (59M + 1M) split between 2026 and 2027.