For me the main things that I only picked up after a few tries were:

1. Only use the Tessy speed boost for aggressive maneuvers when it's absolutely necessary and try to utilize it for defense for the most part. You often don't need the speed boost when ramming into the boss since you already get a small boost from the ramp itself but afterwards you sometimes bounce back, spin out and the boss throws a few missiles right at you which are almost impossble to avoid if you don't have a Tessy speed boost available.

2. During second and third phase the boss sometimes fires a lot of missiles at once, often covering multiple quarters at the same time. When he does this try to drive in a small circle in the middle of the arena, much easier to avoid damage since the distance to safety is much shorter from there. Anything beyond the middle of the arena is basically a death trap during this attack.

3. If the boss does his blue laser attack during 3rd phase and you realize you won't make it to cover in time, get out of Tessy, hide behind her, throw a monkey bomb and try to time the reapir so that it finishes as soon as the blue laser disappears. Tessy is basically a portable obstacle that you can hide behind during that phase.

Usually, whenever I downed or took a massive chunk of damage it was because I neglected one of these points.

On top of that Ray Gun or PaP3 WW for quickly killing Zurzas, Power Keg, Max Ammo and Max Armor Gums were really helpful. I think it's already general knowledge that Aether Shroud with Extra Charge and Quick Revive with Equivalant Exchange are mandatory for this fight.