Has anyone used or has direct experience with someone using these types of
flashlights for SCUBA?

Although many are 'water-resistant' to over 100ft, most have disclaimers
against used for SCUBA.

Among 'expedition' and caver sports-people, there is a 'thing' for
flashlights.  They particularly rave about a model, and variations on this
model, for a flashlight called the CC Expedition or Trek 7:

Among the family of flashlights by the company, CC Crane.  Many of their
lights are rated to 160ft-1000ft, typical 0 ring seals etc., and the
advantage of these lights are that battery life is rated >~40 hrs, at full
candela, to 1000s of hours, at ~half maximum candela.  Thus, theoretically
if SCUBA-able, these lights would be most reliable for U/W and surface use
[no heat] as a general purpose or backup light. With infrequent battery
changes, there's less likelihood of a contaminated 0-ring flooding the
light at depth, nor a need to carry backup batteries.  Its disadvantages
are it doesn't put out as much candelpower relative to a xenon or similar
bulb [thus it has seven bulbs], its beam doesn't throw as far as a spot
light, it runs from $50-60.

Here's a comparison of its candlepower versus a AA Maglite and other LED

The beams were photographed at 5 feet, and a fixed exposure setting allows
a relative brightness comparison.

In a detailed search, I came accross a model called the Tektite,
which seems to be the same thing, now marketed to divers:

Comments welcome.

Warm regards,