Nicolai have been doing this for a long time. My youngest daughters bike was originally commissioned by Simons_Nicolai-uk back in the late 2000s I am told for his partner, its a Nonius design, which at the time could be made smaller than a Helius, with a 12.5" ST. It has similar geo to the bike shown in the article, tho built lighter in this version with a bunch of my old 26" parts and a custom Mojo shock, so is pretty conventional in proportions. It's a 130mm/130mm with a 68HA in this form. She's been on this since age 10 and about 4'7".
Orange did the same with the Diva, a long and std version which eldest daughter has been riding. That bike was actually the same as a 14" five. The addition of a 35mm stem, angleset, 100mm dropper and 155mm Canfield cranks brought it easily within the bounds of a 4'9" 11 yr old. This one is 140mm/140mm and has a standover of just under 680mm.
So it's been wholly possible for a long time if you were committed to it for your kids, either through a custom route or carefully selecting components.
What I wanted to do was take the forgiveness and confidence a GeoMetron provides with the same geo and apply that to kids bikes and smaller people, make it really accessible, drive the standover below that of even a 26" Diva (the new XS GeoMetron is 660mm) but make the reach and HA, WB etc forward thinking. So they don't have to think about 'adapting' or riding differently, it's what they know from the start. Both of my kids have been riding long, slack bikes for their size since 6 (When they had 14" OnOne Inbreds with adapted SID's, 24" wheels, 30mm stems and modified cranks at 145mm, the Inbred has a super low standover) I've compensated with the setup so long is normal to them. Neither of them are super great or super fast but they enjoy it, are confident and happy to ride lots of stuff, do some jumps and drops, ride down steps etc. so it's been a win from my perspective and keeps me closer to my girls with a shared hobby.
Can't wait for the GroMetron to arrive..
if anyone wants ideas for their kids bikes or help and what parts can be used to good effect now low cost 26" parts just ask or msg me, here's the bikes I built for mine. 14" Five or Diva is ideal from 10-11yrs (or earlier if they are taller, but hard to find used. However Orange will refurb it for £200 to look like new.
There are some parts worth investing in like the cranks and suspension. Deore 11spd or SLX is now cost effective..
[img]IMG_0769 by Phil, on Flickr[/img]
IMG_0296 by Phil, on Flickr
IMG_3424 by Phil, on Flickr