Yes those aluminium screwed ones look horrible, do they not. If you google "threshold strip without screws" you should be able to find many types which either have self-adhesive strips underneath to stick directly to the subfloor or come in two parts, the lower being screwed or stuck to the subfloor and having a channel on top into which the upper visible part is simply pressed.
Probably not directly relevant to your current issue, but I have just fitted some engineered oak flooring in a room with an oak threshold strip which I somehow (even with my crap woodworking skills) managed to cut to a size that just fits nicely and needs no fixings of any sort (see pic). I dare say it may come a bit loose when the weather gets colder but it's ok for now. You might perhaps be able to do something similar with two grey-painted stripwood lengths, depending on how rigid the matting is.