We tend to use TOTL, MOTL and BOTL as comparison figures of speech rather than be pedantic in their use strictly in the context of the product lineup of that specific manufacturer, Donny.

I don't seem to recall anyone using the term TOTL for the BK-5, despite that being its literal place before the BK9 came out.

Mind you, Roland themselves use the term 'Flagship' for the BK9. Not exactly encouraging, if you (like me) are actually wishing for a REAL TOTL arranger.