Hey, what's up? I don't run 7th Dragon and, in fact, I haven't even played past the prologue (I run 2020, though). But I've got some info I think might be worthwhile for those reading this.
First, there seems to be a Japanese runner named Peta who has allegedly achieved an Any% PB of 3:38:49. I say allegedly because, due to niconico's archiving system, video proof doesn't appear to be available. I am, however, inclined to believe that the run is legitimate due to the sheer quantity of information about the game this person has posted to their blog and Twitter about 7th Dragon.
Peta's Blog: https://translate.google.com/translate?hl=en&sl=ja&u=http://akmeda.3rin.net/&prev=search Peta's Twitter: https://twitter.com/7thRTA/media
And although video evidence is absent, Peta has apparently typed out the route they used from start to finish, which you can find here: https://translate.google.com/translate?hl=en&sl=ja&u=http://peta.sdbx.jp/%25E3%2582%25BB%25E3%2583%2596%25E3%2583%25B3%25E3%2582%25B9%25E3%2583%2589%25E3%2583%25A9%25E3%2582%25B4%25E3%2583%25B3RTA%25E3%2583%2581%25E3%2583%25A3%25E3%2583%25BC%25E3%2583%2588/7thRTA%2520ver4.01.pdf%3F__module%3Doff&prev=search
Lastly, there is an annual speedrunning marathon in Japan called "RTA in Japan." Presumably due to COVID-19, they've switch to online delivery this year, and have just opened submissions. One submission, interestingly enough, is 7th Dragon Any% with an estimate of 4:20:00 by a runner named sora. I haven't been able to track down video evidence of sora's runs, either, but I'm preeeetty sure I've got their Twitter. So, there is at least a non-zero chance that there will be a marathon run of this game in a couple of months.
RTAinJP Online 2020 Submission List: https://translate.google.com/translate?hl=en&sl=ja&tl=en&u=https%3A%2F%2Frtain.jp%2Fplayer%2Fsubmission%2Fgame%2Fsubmission-rtaij2016%2F&prev=search sora's Twitter I think?: https://twitter.com/sora_soramame99?lang=en
I apologize for the absolutely garbage formatting.