Currently the default order for Thai glyphs puts them in shape groups (so กถภฤฦฎฏญ to start).
While some designers may tackle these first, we would not want our Latin letters to be presented starting obpdqnmhru. It’s misleading (newbies think this is the real alphabetic order) and unnecessarily directive (it’s actually more useful to draw a selection of DIFFERENTLY shaped letters to start, to see how they work together, than to design lots of similar letters and later realise they all need adjusting. At any rate, it’s not up to the software to present which letters should be drawn first). It also makes it hard to find a particular letter when you know alphabetic order.
Please also remove ru-thai.short and lu-thai.short. These vowel letters never take diacritics and will never require alternate versions.