Fellow Wikipedian Michael Brückner, now working at the Naresuan University in Phitsanulok, in his working blog posted about two papers co-written by him. Though I can only access the second on GIS in Thailand, one of the problems they are trying to address is the identification of toponyms with the actual location, something which I also often have problems with during my work with the administrative entities.
As I am now only using Thai sources at least the problem of the plethora of romanization schemes does not affect me, and where I use "English" names to make it easier to read I exclusively use the RTGS (Royal Thai General System of Transcription), which though it has its weaknesses is at least a standard. But spelling changes in Thai are also possible, not just the temporary spelling reform of the 1940s, but also minor changes, like an added or removed ะ, or the omission of a silent last letter, both does not changes the pronunciation at all. One example can be the spelling change of Thep Nimit in Kamphaeng Phet, which changed from เทพนิมิตร to เทพนิมิต in 2005. Strangely I can only find the announcement for the rename of the TAO, but not the one for the subdistrict itself. And there are also accidental misspellings, sometimes even in the Royal Gazette. But as I work through the entities mostly manually I can identify the entities in these cases much easier than a computer would do with a simple search.
However much more work are the real name changes, and even worse name exchanges between two entities. Most problematic are names where I cannot find any current corresponding entity, and no source for a renaming or abolishing. One example is the minor district Hua Hin (กิ่งอำเภอหัวหิน) in Tak Province, which was created in 1906. And this announcement is the only thing I have found about this minor district so far. Its parent district Chiang Ngoen was downgraded to a minor district before 1917, and at an unknown date abolished completely. The only thing how I can link this Hua Hin to the present day entities is its main tambon Wang Hin, which is now under Mueang Tak district, same as the tambon Chiang Ngoen. I haven't yet lost my hope to find more about this minor district in the Gazette, but at least among the announcements I could find by searching for the titles there is nothing yet.