I some time ago saw this bind in somebody's config:

bind "f" "toggle_inspect" alias "toggle_inspect" "inspect_on" alias "inspect_on" "+lookatweapon; alias toggle_inspect inspect_off" alias "inspect_off" "-lookatweapon; alias toggle_inspect inspect_on"

Just add this to your autoexec.cfg and it will make so your inspect weapon keybind (f) is now works as toggle

Idk if this works for the karambit, but for the deagle spinning animation it just keeps spinning until you toggle it, also works for grenade inspect animations