I would definitely waive Smyly. I'm much closer to an xFIP absolutist than most, but we're 300 innings into Smyly's Cubs career and he's outperforming his FIP/xFIP by half a run. The margin for error isn't huge as we saw when he was getting hammered last summer, but I think there's some legitimate soft contact skills there, though his 2.88 ERA clearly has a healthy amount of luck baked in.
That said I'm less interested in him and his merits and more interested in the roster spot. The need isn't as dire after Neris got cut, but I think what sets up the team best for 2025 is evaluating as many young pitchers as possible. Wicks, Kilian, Keegan Thompson, and Daniel Palencia are all guys who could really stand to get some MLB time pretty soon here (in that order IMO).
Roster expansion will open up a spot, and Ethan Roberts can and likely will get sent down soon. So it's not a travesty if the team lets Smyly play out the string. But it feels like the full court press on getting interesting Iowa arms some MLB innings is the most appropriate play right now.