My mods upgrade progress almost stoped.

Well, this was quite dramatic.

No, you won't hear content creators saying this is a problem, because while they may be gone from episode track, we now have SRIII, and what's more, SRII gives more of them than before as well. So your predictions about this becoming a problem for everyone is not likely to come true.

There's always some hump for younger accounts to get over, which they eventually do. Quite frankly, it's perplexing to me that these things are even a problem for anyone when the blue cylinders and some of the other pieces are more of a bottleneck. You actually have to get to 6* before you can use these, and then you only need them for one upgrade level. They are also farmable on 9-D, so it's not like there's another source.

Errata: They don't disappear until you get to 6-B. Still doesn't change that blue cylinders, trapezoidal prisms, and heck, even yellow fans are more of a problem.