Why - I am also driving Susvara, HE-6 on the WA33 "past 12 o'clock" - from a power perspective the WA33 seems to be a good match for the Stealth.
I am a big believer in "more power helps more" (I have only ever owned V8 engine cars in the last 30 years
)
Part of my motivation to add the Stealth to my collection is because of its apparently fairly unique sound signature - I tend to listen to 3-4 different IEMs and headphones in the course of a day ... in many different modes, between focused and background listening. The promise of finding a more neutral presentation (from a "slam" perspective) with sufficient details and correct tonality could be very appealing e.g. to listen to progressive rock, complex heavy metal, or opera (e.g. Wagner's Ring) to find a different appreciation compared to the usual suspects (Utopia, HE6, D8000 Pro, Susvara, EE Odin, ...).
Sony MDR-Z1R is a similarly unique headphone that I am keeping around for much the same purpose - to provide a completely different flavor when I'm in the mood. Actually prefer my good old Liquid Fire for that one over the WA33