Automatic Model change for specific tasks and in middle of workflows

As identified in

• #4807

ability to manage Claude Opus token usage becomes critical issue for Max20x users with upcoming limits changes,

therefore we need to have plenty of new solutions and approaches implemented.

I still, can not :

• [ ] change /model MODELNAME in middle of workflow execution...
• [ ] change model for selected sub-agents while they execute
• [ ] assign stronger model for specific problems and tasks (so basically ability to define model routing config)
• [ ] or define own MCP server or external tool that would be used for decision making which model to use for given prompt/conversation...

Therefore we are in the middle of August, after in last days trying alternatives to prepare, I tried Today to work a bit with Claude Code, model Sonnet was too weak, so I switched to Opus and I see "Approaching Opus usage limit", and we are not even on new limits that were announced with end of August... with new limits Claude Code Max20x subscription may become useless without plethora of new solutions introduced to mitigate impact of new limits...