GR translation: but it’s never discussed except in a general way

[Mike Jing]

V650.1-7, P663.4-10   Byron soon enough becomes a Permanent Old-Timer.
Others can recognize his immortality on sight, but it’s never discussed
except in a general way, when folklore comes flickering in from other parts
of the Grid, tales of the Immortals, one in a kabbalist’s study in Lyons
who’s supposed to know magic, another in Norway outside a warehouse facing
arctic whiteness with a stoicism more southerly bulbs begin strobing
faintly just at the thought of.

My understanding of this part is that Byron's immortality is never
discussed except when tales of other Immortals come in, and even then it's
only discussed in a general way, is that correct?

Secondly, the clause "who’s supposed to know magic" refers to the
lightbulb, right? The published translation treated it as if it's about
the kabbalist, which doesn't make sense grammatically.

Thirdly, the phrase "facing arctic whiteness with a stoicism . . ." is a
whole, and its subject is the other light bulb. The published translation
thinks the phrase "facing arctic whiteness" modifies "warehouse", which
seems obviously wrong.