Thanks a lot!
I've done some procedural tilemap generation recently albeit in Unity using 3D tiles. Since that's challenging and fun I want to make that possible of course. Theoretically generating an entire tilemap from scratch at runtime should be possible but albeit only by including private headers at the moment. I'll look into making all of the map classes "writable" without cluttering the interface too much.
But you can get started rather easily by preparing the map in Tiled (at the minimum add the tilesets and the layers you need) and then just generate the tiles on the fly. The API has setTile:at: methods, you just need to know the tile GIDs.
"Streaming large maps" is one of the nice-to-have features (scroll to the bottom). I find that interesting too, and should work with both generated chunks (and saving them, ie the TMX writer is needed for that) as well as dynamically separating huge world maps into smaller chunks (maps so huge the tile data alone would amount to tens of megabytes, ie beyond 1,000x1,000 tiles and several layers). I won't make any promises but it's one of the things I find exciting to implement.