Not OK on mobile Firefox: displacement maps do not apply, so there's no actual refraction, the liquid feeling; there's only the specular effect at the edges. Try opening it in a Chromium-based browser and compare.
backdrop-filter is supported by all major browsers, but specifically using SVG filters, which are more powerful and is out-of-spec, is only supported in Chromium-based browsers.
Not sure if this is relevant, but while moving the slider around, in chromium i see 40% gpu utilisation, while in firefox less than 20% (macbook m3 pro). I do not observe any noticeable difference otherwise in terms of quality.
PS Neat website and explanations, but talking about the liquid glass as a design principle in general, I would rather ui elements in a random website not use that much of gpu for not great reasons but maybe that's my problem of not thinking different.
