OK, so what *are* all those right-turn holding patterns depicted at
each MAP in the "CAP Instrument Procedures" ? (I am looking
specifically at CAP-2, for example NDB/DME 16 at Nanaimo, but almost
all have it).

On this approach (NDB DME 16, Nanaimo, BC), there is no holding
pattern depicted at the MAP – look closely. I don't know what you are
looking at but these holding patterns are rare. They are only found
in mountainous areas and are for shuttling procedures. Some are to
shuttle down for the approach and some are to shuttle up for a safe
altitude.
In this specific case you fly to ARMAC which is the IF. If you're too
high for example coming from the west (minimum safe altitude 7000)
you shuttle down to 2400 as per the holding pattern (thin line). Once
you're there you proceed normally as you would far a procdedure turn
(i.e. race track pattern). Inbound you can then descend to 2000.

Gerd Wengler, ATP