I don't see how your interpretation of 725.136(I)(2) permits a low voltage pair of wires to be enclosed within the same cable or raceway as conductors for light and power.
I would interpret that 725.136(I) refers to "Other Applications" such as when the 2 cables cross paths in general construction areas of buildings.
Well....I believe in quite a few previous posts I explained that but let's look at it this way so I don't want to be redundant. Also UL issued a CRD which permits the application and confirmed it meets Section 725.136(I)(2).
ok so let's look at 725.136(A)- General Rule
(A) General. Cables and conductors of Class 2 and Class 3
circuits shall not be placed in any cable, cable tray, com-
partment, enclosure, manhole, outlet box, device box, race-
way, or similar fitting with conductors of electric light,
power, Class 1, nonpower-limited re alarm circuits, and
medium-power network-powered broadband communica-
tions circuits unless permitted by 725.136(B) through (I).
So of the items in (B) through (I) the only option that applies to the Type MC Cable is (I). So this gives a separation specific to those issues not covered in (B) through (H). Now notice the allowances given in (I)(1) and (2) below:
(1) Either (a) all of the electric light, power, Class 1, non
power-limited fire alarm and medium-power network-
powered broadband communications circuit conductors
or (b)
all of the Class 2 and Class 3 circuit conductors
are in a raceway or in metal-sheathed, metal-clad, non
metallic-sheathed, or Type UF cables.
(2) All of the electric light, power, Class 1 nonpower-limited
re alarm, and medium-power network-powered broad-
band communications circuit conductors are
permanently
separated from all of the Class 2 and Class 3 circuit con-
ductors by a continuous and firmly fixed nonconductor,
such as porcelain tubes or exible tubing, in addition to
the insulation on the conductors.
Both of these options were expressed in the UL CRD and meeting the NEC 725.136(I)(1) and (2). The jacket on the Class 2 conductors were increased to 30 mils (like Type NM-B) to meet (I)(1). Without a set standard for the jacket thickness the equivalent Type NM-B was chosen.
My previous posts go into more detail but beyond that I guess we would have to agree to disagree....but we all make it now and it's called Type MC-PCS.
Hope this helped..if any