The character '!' is not being used for anything, and is also not easy to be mistyped. The idea is to allow the users to just type "!amazon" at any place of the result page without having to change the query string (just like how we can already type just 'i' to go to images).
To help tracking what is being typed, a little dark and transparent box (similar to the current shortcut helper but much smaller) can appear. Having to press enter at the end should make things quicker and more intuitive too,
This will also help with better integrations in the future, considering the existence of regional bangs and the coming AI bang, all which don't need a URL redirect (it's still kagi.com, the query box doesn't need to reload).
