Richard,
The issue you raise with Studio happens with ALL keywords.
Try typing
DEFINE form, begin, end, to DATE
and
MENU ""
ON ACTION insert
ON ACTION update
ON ACTION delete
END MENU
and note that from, begin, to, end, update, delete, insert are all uppercased. In simplistic terms if you have the preference enabled, as you finish typing a word ie a space, Studio is looking to see if the word is in a list of keywords, if it is upper case it. There is a little bit of logic as it can detect if you are in the middle of a string and not upper case, but not a great deal of logic.
If you are participating in the Genero 3.20 EAP which is on now, you will see that there is a new code beautifier, and that is clever enough to detect keywords when they are used as keywords and upper case them appropriately. Interestingly that code has to compile cleanly in order for the code beautifier to do its thing. So if you have not already, please sign up for the EAP
https://4js.com/download/eap/ and provide feedback on the code beautifier and other new features.
Reuben