Do we need to invoke getTile for each tileCoords to pre-generate tiles?

[jsinterface]

This part in the readme doesn't seem obvious to me:
To pre-generate tiles, we need to set maxZoom and indexMaxZoom to the same value, indexMaxPoints to 0, "and then accessing the resulting tile coordinates from the tileCoords property of tileIndex."
The toleCoords property is just a list of tile coordinates, so does this mean to say we need to invoke getTile with each, or the tileCoords array has some "get" proxy behavior to complete the tile generation?
My assumption was that after I pre-generate tileIndex with the proper configuration, I can just continue to use .getTile and they'll be just there. Apropos, it's also not clear if setting "maxZoom" and "indexMaxZoom" to eg. 15, means that i won't be able to getTile above zoom level of 15? It seems like I can, so the "max" only refers to the limit for pre-generation.
Thanks for clarifying!