In terms of testimonials, you display a grid -- I think you'd be better off choosing your two best testimonials -- getting rid of the grid and present it like books do -- flip a book over and one or two authors will tell you how good this book is -- and that text cannot be missed -- its centered and in a fairly significant font; your testimonials are in a tiny font <-- or maybe do both idk.

The diagram-image... could be more night-mode-y -- the contrast rn is blasting my eyeballs.