Thank you for your interest. For new maps I would recommend FPV Freerider Recharged.
As you may know, Recharged has the full level editor included. That makes it possible to create your own levels from scratch, or download levels that other users have created and made publicly available. (Such as here for example)
You can also simply edit already existing levels - add and remove stuff - which is quite easy and can be a lot of fun.
(The only updates that are planned at the moment are necessary ones).