My personal opinion is that if you can't do a set tile size for isometric in Construct, then it's not worth the effort.
That being said it is doable.
Also there's nothing wrong with using static images instead of Tilemaps.
There's also nothing wrong with using Sprites instead Tilemaps.
Or mixing them...
I'm leaning towards using a static image for 'floor', and then sprites for drawing the map, since I can then use collision to handle where I can/cannot go. Thats how I did my first prototype and it worked well, but then it IS very tedious trying to place the sprites (copy/paste becomes my friend).
I was hoping that someone else had picked up a better way of doing it since Tiled does it so easily.
My only other thought has been to read/process the TMX file manually and process it. I suspect however, if it were that easy it would have been part of the Tilemap process already...
Thanks for the input.
dupuqub, thanks for the post. I've used tile replacement techniques like this before, appreciate the link.