JoJo No Kimyou Na Bouken - Tags for every single part

JoJo No Kimyou Na Bouken consists of currently eight parts, which each feature a different set of characters - sometimes they overlap, but more often then not you can start reading at every part without further background information required.
Yet, only Steel Ball Run (Part 7) and JoJolion (Part 8) are tagged. Some may argue there are reasons for this since SBR is basically the start of a complete reboot for this series and much longer than any other part so far, but I think it would greatly help the search for part-specific fanart if we could create more subtags for this series - much like Precure or Kamen Rider. Of course, each subtag implies the main series for an overall search in this case.

Is this reasonable because of the differences between each part or should we just leave it as it is?

Probably not necessary. It would be pretty cumbersome and inconsistent, considering the first six parts form a strong enough collective continuity with each other. A lot of the pictures are pretty ambiguous, or are group images from multiple parts, what ifs, and in betweeners, in which case it would just be better to search for the characters on their own. Plus, for the cases of characters like Dio Brando and Kuujou Joutarou who keep relatively similar appearances across multiple parts it can cause problems if they're not wearing something that obviously shows what part they're from like in post #1421304. I'd say you're probably better off searching for specific characters to get what you want.

As for SBR being its own tag I believe it was issued as its own series at first, and only later did it start carrying the Jojo name. I think Jojolion is also published specifically as Jojolion, with it being part of the Jojo series being taken for granted.