Great news!
Library confirmed to support Bot API up to the latest v.5.3!
(With some limitations, see compatibility list in readme).
It also includes set of
**register_xxx_handler**
functions, that allows to dynamicaly add handlers in addition to
_bot.message_handler_
This is a pre-release to version 4.0.0. When the maturity of this version will be confirmed - the release will be bumped.