Autosport web reports Stephane Ratel's interview.
https://www.as-web.jp/sports-car/500609?all
He revealed GT300 tire secret (there is a special tire and customer tire in GT300).
*About GT300 BoP
SRO BoP is supposed to be used under single tire manufacturer race.
This BoP is also used in the GT300, but it will also be the effect of multiple tire manufacturers.
I think Bandoh-san can solve this by changing it single tire manufacturer (joking).
I think that current SRO BoP is almost perfect.
However, in GT300, some team use A-level (special/works spec) tire, and another team uses B-level (customer spec) tire, so I believe that this makes a difference with GT300.
Performance adjustment is almost perfect level equality.