Once again these Yashica lenses don't disappoint - they are very sharp, have a neutral colour rendition and offer decent contrast. I also like the fact that they all have in-built hoods. Although in M42 mounts, my favourites are the DS-M range, the DX lenses have proven to be consistently good performers.
While I've seen lots of 135mm and 200mm lenses with built-in, sliding lens shades, I can't think of ever seeing one on a 100mm or 85mm lens.
I just bought an old Miranda (Soligor) 90-230mm zoom for a friend -- in very nice shape. It has a built-in, sliding lens shade, but it is not even 1/2 inch long. My thought? Why bother?
It's always going to be a compromise when supplying a built-in hood for a zoom with a wide focal length. 90-230 is not too bad as that's all within the telephoto range though a 1/2 inch hood even for a 90mm seems, as you say, hardly worth it - unless that front element is very exposed to lateral light. The Yashica 100mm f2.8's hood extends 1 inch from the front element. 100-300mm zooms are generally easier as far as lens hoods are concerned as a hood deep enough, but not causing vignetting, at 100mm should certainly be fine for 300mm. The real problem is when a lens ranges from wide to telephoto as there's no one-size-fits-all solution as far as I know.
With the Contax Zeiss 40-80, the Contax No.2 Hood is recommended and the No.3 Hood for the imperious 70-210 with adapter rings as required. They produce a very acceptable compromise and I use the same Contax No.3 Hood with Yashica's outstanding ML 70-210 f4 to good effect. Your Miranda purchase is unusual as very few zooms were manufactured with in-built hoods.
The Soligor 90-230mm f4.5 struck me as an odd beast, and the one I have (only labeled "Miranda") appears to be pretty old -- although it is in very good shape. Apparently Soligor sold this for quite a long time under various names, and somewhat different body designs -- and lens mounts (fixed [M42, Miranda, ?] and interchangeable [T2, T4, ?]). It makes me think it must have been inexpensive to make. It sort of reminds me of the Minolta 100-200mm f5.6 zoom that they sold for about 30 years! The serial # starts with "1" which supposedly means it was made by Tokina.
As you can see, one has the serial number on the bezel whereas the other has the number stencilled on the barrel. The one showing the number at the front of the lens is the older version; in all other respects, as far as I can see, they are identical.
Minolta did the same sort of thing, a FEW times -- but the only thing that changed was the front ring inscription of the lens.
One example was when they dropped their alphabetic notation of the # of elements and # of groups of the lens on the front ring, such as "PF" or "NL". All of a sudden they dropped that, but the lenses themselves didn't change. It was no big deal, and the odd designation was just confusing to consumers, anyway. For example, their 16mm fisheye was designated "OK", not because it passed inspection -- that was just the optical formula designation.
Years later on the front ring, the notation of the focal length now lacked the "f=", and swapped places with the maximum aperture -- as well as the filter thread diameter was added, and the "LENS MADE IN JAPAN" was relocated. But otherwise, the lens was exactly the same.
I'm sure Yashica and Minolta were not the only companies to fall down this "rabbit hole".