I guess I got the back pressure concept backwards in my mind...seems as if your op rod and spring would take an additional beating with the reduced pressure on the back side of the piston. As far forward as those seem to be, it looked to me as if it would actually go past at least the first one. I had never noticed that feature on the Alby tubes, nor do I think I ever read about it either....they have so many weird features I guess looking at the gas tube is like taking out my contacts and looking at it underwater.
Technically, the gas tube itself is not even required in this style gas system. A Vz58 uses a spring loaded gas piston but has no gas tube per-say or op rod. Now, before one says it's totally different, the gas system and piston works identical between the Vz and SKS, the piston assembly directly unlocks the Vz58 bolt carrier. The Czechs used a highly simplified short stroke gas system, virtually identical to the SKS, and adapted it for automatic fire, instead of dumping gases back into the barrel, they simply got vented under the handguard.
Vz gas piston vs an Ak. The Vz is much like a SKS piston/spring loaded op rod all rolled into one.
Now the little issue with the Czech design, do a few mag dumps, the handguard gets kinda toasty, rather quick, even with a heat shield installed. Which, could be why Albania made the handguard full length and added extra ventilation to circulate a larger volume of cooler fresh air. But, again it's just a theory.
Was Albania concerned with ergonomics? soldier safety? or maybe the three ports per side, and Ak style charging handle, make it appear more Ak'ish to the soldiers? These are plausible, but maybe unlikely Or, was it as simple as make it look as close to a Type 63 as possible, Albania being a big user of this weapon. Maybe they liked the looks, from a distance I would imagine they look the same, even close up, they share some visual similarities. Handguard appearance, double hole butt stock, Type 63 looks mixed with SKS durability, as the Type 63 wasn't really noted for it's durability.
The Chinese T63 And Its Role In Jianshe T56 Production in Chinese SKS (Military) - Page 1 of 2