In my experience, I do not believe Aphantasia has any affect on ability to complete higher math, having completed Calculus and Statistics at University level.
However, I seem to struggle when presented with IQ tests involving logical spatial /picture sequencing. I find every other type of IQ logic tests (numerical, alpha etc) fairly simple.
This has always been an annoyance to me. I could not find a logical reason for my inability to solve picture problems and practice did not resolve my issue either. I would feel quite stupid at times wondering why others didn’t have to draw rotations like me.
So Aphantasia is the answer, I couldn’t imagine the ‘random’ image rotating so I couldn’t query the logic change, unless I drew the image.
I only read about Aphantasia this year and I have only seen what I believe to be visual images while dreaming. I believed ‘visualize a beach..’ was a figure of speech and as a child I counted sheep by hard-blinking my eyes to create a noise to represent the sheep.
Again, this is only my experience. Others may have a different experience.
But all in all, not being able to see an image has not affected any other aspects of maths calculation, when I solve I extract the unseen formulae and calculate still arriving at the answer.