Well I more or less have a solution for this...
Before I go on however though I'd like to say that Bleach Characters are not Mach 29 they're Mach 29+ from SS Arc Bankai as be completely blitzed Byakuya's Bankai which is mach 29 without even using his full speed...
Now that that's out of the way regarding the scaling of this thing I'm a little iffy on it.
The current MHS+ for the rest of the RG members and the Elite Sternritter are from Ichibe's feat... yeah it doesn't seem right to place them at the exact Mach 3500 from Ichibe as he is their leader and should be stronger than them but it also doesn't seem right to place them at MHS as I seriously doubt that Ichibe is over 10 times faster than the rest of the RG. Also Senjumaru blitzed the hell out of Nianzol Weizol (who should be scalable to Bambi fodder's MHS feat).
So for the RG the MHS+ stat should stay but it should be mentioned that they are not mach 3500....
Now the Elite Sternritter... ok I can't say I agree with placing them at MHS+ as we didn't even properly view their fight with the RG members. So for them their speed stats should be: At least Massively Hypersonic, possibly Massively Hypersonic+...
Now we come to Kyoraku... well he should likely get the same scaling of: At least Massively Hypersonic, possibly Massively Hypersonic+...
Now we come to the main problem... Should Pre-Timeskip Kyoraku be MHS sure but should he be MHS+... I don't think so...
Reasons why:
1) He didn't use his Bankai against Starrk. We know why but I do think that he could've moved away from where the other fights were lured Starrk there and used it. Which leads to my point: he wasn't fighting seriously...
2) Another reason why he wouldn't fight seriously is because it should be obvious that he'd try to conserve his energy to fight Aizen.
Now another thing I would like to add here is Gin's Bankai of Mach 500. Now before everyone says he lied. I'd like to say two things... well one thing actually...
1) We don't know if he lied to both Ichigo and Aizen for all we know he could've said something different to Aizen. But this is a useless point as I can come up with two reasons why he would tell the same thing to both Aizen and Ichigo...
2) Even if Gin did lie to both Aizen and Ichigo. I highly doubt that Ichigo wouldn't notice if his bankai was far slower then what Gin said and same would Aizen hell it'd be impossible for Aizen to not notice if Gin's Bankai speed was so much slower than what he said it was...
Because of the above reasons I wouldn't really say that Gin's Bankai speed isn't MHS even if it isn't Mach 500...
Now the speed stats...
For the RG members besides Ichibe: Massively Hypersonic+
For the Elite Sternritter and Post Timeskip Kyoraku: At least Massively Hypersonic, possibly Massively Hypersonic+
For Pre-timeskip characters (Base, Form 1-3 Aizen, Starrk, R2 Ulquiorra, H2 Ichigo, Gin Ichimaru, Yoruichi, Isshin Kurosaki, Urahara Kisuke): Massively Hypersonic.
For Final Form Aizen and Dangai Ichigo: At least Massively Hypersonic, possibly Massively Hypersonic+ (Reason for this is because Aizen in just his first transformation really just stomped the hell out of Isshin, Urahara and Yoruichi at the same time. I also doubt that any of the Royal Guards bar Ichibe are stronger or faster than them.)
Now I'm sure someone's gonna bring up the "Aizen failed to react to Gin's Bankai thing" well that was in his second form and well it seems more likely that he didn't avoid Gin's Bankai on purpose because
he already knew Gin was gonna try and kill him and was actually interested in knowing what Gin would do to take his life and there is also the possibility that Aizen wanted to test the his current limits. Even still if they actually get this upgrade only Final Form Aizen should be placed at At least Massively Hypersonic, possibly Massively Hypersonic+...
Well this is my analysis of things and it should make things a little more logical...