Submitting this on behalf of a user who reported it via the support mailbox:
Assistant pasting of very large texts freezes it for long periods on Pixel 6 Pro running Graphene OS Vanadium (Kagi Ultimate plan).
The Assistant should allow pasting the text without freezing or give an error if it exceeds the limit.
Always about BEFORE the submission button becomes available.
The handling of "large" text junks, say at least 1000 chars or much longer, appears to freeze the entire tab / view
This is always eventually resolved, but it can take more than 30 seconds for the tab to become UNFROZEN.
Phind, ChatGPT, Claude (which hides large texts sometimes from the messages) all can take long texts smoothly. They are maybe in order of speed, based on nothing my personal intuition and guesswork from experience, Phind (always less than 2.5s) > Claude (always less than ~ 4s), and ChatGPT (occasionally unreliable but around 2.5 - 4.5 s max.
The attachment functionality in Kagi works fine and can be used as workaround.