SAT or ACT Prep in the summer

I’m currently struggling about whether to take the ACT or the SAT.

I’m a rising senior, and I’ve taken the ACT 3 times (with scores 30, 30, and 32). The only reason I got a 32 is because I aced the math and science - I only had a 23 in the ACT Reading section ALL THREE TIMES.
I took the redesigned PSAT and got 1340/1520 (weird scale, ik).

I also took a online quiz suggesting which test to take - the answer: take both.
I plan to prep for standardized testing in the summer, and I’m not sure which one to choose.

Here’s my personal analysis to choose each test, but please correct me if I’m wrong.

ACT
PRO 1: I’ve taken ACT 3 times so I’m more familiar with the format.
CON 1: There’s little chance that I boost my reading speed and increase my reading score to a satisfactory one. PLUS there’s no room for me to improve my math and science score, meaning I have to depend on my English and Reading.

SAT b/c
PRO 1: I’m a slow reader. More time and more variety of passage types in the SAT reading section would give me more advantages.
PRO 2: If I can achieve a high score (~1500+) in the SAT, I don’t have to submit my previous bad ACT scores. So it’d be a single-sitting high score. right?!
PRO 3: Khan Academy SAT prep
CON 1: There are limited practice materials out there.

Please advise me on what to do. *** but I don’t really have the time and willingness to take both tests :frowning:
And please suggest any prep plan or materials that might be helpful for me (English and Reading in particular!!!)
THANK YOU!