Both the Fubuki and Tensei AV Red shafts are high launch-high spin. To get the Fubuki in a regular flex you'll need to get the MV IR 55 (the MV IR 50 is an A flex).

A great shaft reference is the Custom Club Options booklet:

media.titleist.com/.../Titleist-Clubs-Custom-Options.pdf

I received the Fubuki IR 55 R shafts in my new T300 4-53. Jumbo tour wrap. 1'5" longer. October 2021.
Originally supposed to be the Tensei graphite.
Due to a shortage of shafts received the Fubuki shaft.
Im a 63 yo, haven't played for 12 years, but these shafts have not let me down on distance. 7 iron 150 metres.
Playing on 5 Very happy.

Love to know how long you waited for your clubs. I’m waiting for my T300 with the Kubuki MV 50 shafts.

Hi PGroves......Would also love to know when you ordered and if you have received your clubs. I ordered T300 with Tensi graphite and also changed to Kubuki. Ordered Sept 2021 and now March 2022 and have not received them.