Obviously projecting out this far is a fool's errand to begin with, but I'm basing this thought off of the Palat contract. The assumption here is that you buyout Palat to find the extra money for Nemec.
Using the cap friendly calculator, Palat's buyout in 2026 would be $2.7 in 26-27 and $1.65 is 27-28. If Nemec burns a year this season, and using rough estimates for Mercer and L. Hughes extensions and general costs of filling out the roster, I think it's safe to assume you'll need to conduct the buyout (or trade Palat to a salary farm). If his ELC slides, you can probably just ride out the Palat contract.
I get the appeal of burning a year to reduce the value of the 2nd contract, but that may be a better idea in a vacuum than it is here.
Granted if he did slide then you also have to re-sign both him and Nico in the same offseason so who knows. Like I said in the first place, it shouldn't factor into if he makes the team or not anyway considering we're in a win-now window.