Interesting read,
For what it's worth,
1/10 has an almost exclusively emulsion shock design, since, well forever.
1/8th has use a bladder design almost exclusively for most of its age (in the last 5-6 years, some Mfg.'s have played with the vented cap styles here and there)

For whatever reason, the engineers/designers have traditionally stuck with those two designs for those two scales

More recently it seems that a number of Mfg.'s on the 1/8th side are playing with the emulsion cap designs and only Tekno offers all three shock/shock cap designs in their kits (emulsion, bladder, and vented). As for which is better and older what conditions, I have no clue, but I'm pretty sure there's reasons by those whom are probably far smarter than most of us as to why they would want to use one design over another or, why they would be offering parts to switch designs.