I've been using TV aerial antennas for the past 12 years for miniature mics and actives which has worked great for me. Total usable span using two extending outward from a central mounting point at the stand is about 6' (2m) total, with one or two of the smallest diameter sections remaining permanently retracted and gaff-taped in place as they are too spindly and flexible. I've even attached full body mics on them at short extensions of around 2' or so in addition to the miniature DPAs further out. The ones I use are repurposed from set-top TV antennas as those are the only ones I've been able find which are black-finished rather than chrome-plated, which is a personal requirement for me.
Otherwise what I am using is similar to those linked above, but with the mounting screw axially-aligned instead of at a right angle - an arrangement required for my mounting system where the telescopic sections always remain attached to the central mount which usually remains attached to the stand as well during transport, with the telescopic arms folded down so as to be parallel to the collapsed stand. You will want to devise some method of supporting the telescopic sections just outboard of pivot point so that you do not have to rely on hinge-friction to hold the bars horizontally. I use a short piece of stiff wire which extends from the central mounting point over which the antennas hook, and can bend them as needed to adjust level or elevation angle of the bars. Photos and details are in the Oddball Mic Technique thread if interested. The system I'm using currently does not include shock mounting other than the springiness of the bars, but none is required for omnis. I can hear some handling noise in the directional mics when I'm manipulating the stand, which has never been an issue during recording, but will likely incorporate some sort of shock-mount between stand and central mount point in my next revision.
The telescopic trailer-alignment system bars Moke is using are larger diameter and can probably support more weight, at least at short extensions, and may be a better match for heavier mics. Unfortunately they don't seem to be available with a black finish and don't include a hinge if you want those features. Work around for chrome bars is using a strip of gaff-tape to make them black, but then they are no longer adjustable/retractable.
I like the thin-diameter black TV antennas which have been strong enough to survive some crazy FOB situations over the years and are visually nearly invisible in low light.
If anyone comes across sources for black finished telescopic antennas or the like, please let me know. Will be seeing if I can do something similar using thin carbon fiber tubes now that they are available in more sizes and at less cost than ever before, but the telescoping feature is the constraint to figure out there.