Presets for custom instructions and chat-specific, editable custom instructions (+ increased character count)

On the website, for the Plus feature “Customize ChatGPT”, it would be nice to be able to save presets that we can toggle on / choose for chats. And not just saved presets, but ones that can be chat-specifc and editable. As it stands. changes only apply to new chats, and globally. Having them be chat-specific and editable would obviously allow you to change custom instructions per each chat without it being a new chat. There can still be a global custom instruction, with the capability/choice for the chat-specific one to either override or add to the global custom instruction.

It’s easy to do custom and chat-specific instructions via API with a proper frontend, but would definitely be nice to have these on the website too. Also, an increase from the 1500 character limit would be great.

So, in summary I suppose my response features 4 requests here in one.
1. presets for custom instructions
2. chat-specific custom instructions that are also-
3. -editable (no new chat needed to take effect)
4. Increased character limit for instructions