S rank metal sonic boss battle ?

[SeleDreams]

Hi, i post this because i find something weird
I'm playing in the high difficulty mode, so all the rings are dropped when we take a hit but we can recover them
i'm trying to get the S rank to all sonic forces levels, but i've a big difficulty to get S rank at the metal sonic boss fight, i tried multiple things
i always get the perfect at the QTE to destroy the eggman robot and i grab all the rings before the battle
for the metal sonic battle, i tried to be as fast as possible, i get a B rank
So i tried other things, such as making the fight really long by not hitting metal sonic to destroy more eggman robots to get more points but in this case either i get a A rank but not enough time points to get the S rank, either metal sonic starts to fly and i get immediatly a "try again"
have you some tips to get the S rank at metal sonic fight ?

[pythonfp]

I tried to go max speed most of the time with the wisp boosts without getting hit, got a S rank without trying getting max rings and destroying robots. My avatar was a wolf attracting rings though...

[pythonfp]

Just retried it, S rank without getting hit, time 2 min 33 s with 106 rings collected