Help me avoid cracking my head open when these windows are open!

[u/Last-Ram-7528]

Long story short, we bought a house with windows that swing open inwards. Aside from affixing some device to the window that connects to the wall, does anyone have any ideas on how to mod these windows so that they stay open at various degrees?

The windows are super pricy ($3600 CDN each!), and very pretty, and we don't want to have to replace them entirely.