Improvement of Threads

### Your use case

#### What would you like to do? I would like to be able to make a thread full screen

#### Why would you like to do it? I do a lot of play by post games and threads are how I prefer to manage multiple scenes.

#### How would you like to achieve it? allowing threads to act more like sub rooms

### Have you considered any alternatives?

I have considered managing a collection of rooms to manage it but considering I will often have hundreds of threads I gave up on the idea as it would be too onerous.

### Additional context

When you pin a thread it creates a white border that obscures the edges of the text line.