I find 5.6 Sol will pick a direction and aggressively pursue it in long horizon tasks. I've got it porting an older game from Pascal to my own game framework. I gave it some instructions on doing a full 1:1 port. I had already ported the game rules and multiplayer support to a very different system than the original, but all of the UI and features and such needed doing, and needed to be integrated into this very different system.

The first attempt it had files tracking both hashes and semantic hashes of every individual line of Pascal code, mapping to what code in the port is responsible for that line of pascal. It had written tooling to parse Pascal in service of this for some reason as well. I asked why it was doing this, it said it was because the reference code is .gitignore'd so it needs to thoroughly maintain the mapping in case someone working on it does not have the reference code, or in case the reference code changes.

I started over with Claude 5 Fable, and with better instructions about focusing on UI. I got a long ways with that before I hit my weekly limits, and switched back to 5.6 Sol. It picked up and did a great job for a while, although it interpreted my desire for a 1:1 port to mean every pixel must be perfect. I let it go on and it did some good work in that regard, but then it decided it must perfectly reproduce a hash of the game state in various replays & etc. It had clearly lost track that I didn't need game rules ported, and it found that the original code produces a hash of the gamestate for various purposes, so it ended up reproducing this in a game that represents its state totally differently. It also rolled its own version of Pascal's RNG source in order do this. I've burned through 3 weekly limit resets on this to see if it's actually going anywhere, and it has found some bugs, but man it is going hard in a direction I didn't even ask for.