I made that proposal some time ago also without much response. May be we should ask fly_so to start an official section for that. I would offer my templates.
I noticed that your templates are faulty in that manner that you also filled the border stripes of the 16*16 square. Result will be that the buildings will overlap here when using the autopop. There must be free stripes at all boarders as wide as marked with the black edges.
Well, using your tool is still the only way to populate a map with more than a handfull buildings, so it's essential. I think it's not so often used, because it's quite difficult to handle and to edit a big actors.static, but in my opinion there is always somthing wrong with a map if there are only 5 buildings even in a capital city. Handling your tool isn't easy, but that's the same with other aspects of mapmaking.
Just one other point: There seems to be some sorting of the buildings depending on their x- and y coordinates. Very generally said it seems, the fmb sorts from high x- and y-coordinates to the low ones, but in little it is very confusing.
Autopop generated files run fine even if they are verty big (20 MB and more). But even quite smaler files don't run, if there are a lot of buildings (Like airport buildings, custom brideges, railway stations and so on) added to the autopopfile buildings.txt afterwards. So i can not add all objects to my inBuildings.txt i planned.
Reason may be, that the ators tool - other than the fmb - doesn't sort. So i think, it's a sorting problem. The game seems to handle only a limited number of unsorted entrys (And it seems, that also the grade of dispersion of that objects matter).
There is no problem with the autopop generated files alone, so i think there the sorting is right. But what algorithm do you use here? Even if you "only" copy the structure of a template you must somehow shift it depending of the place of the city textures in the map_t. I never understood how the tool works, but it seems you are doing something right here ;-). Do you know the secret of the sorting mechanism?
I'll be happy to share my templates, though I expect they could be improved with a little more work.
I would just like to add some variety to my map and i am too lazy to do the templates by myself. Below is a link to templates that i did on my own (nothing special though) and if you have any to share, post the link here.