ugh, the feet. the hoof angles... ugh. I was also considering this horse for myself, and hoping to hear how flexions and be misleading etc. block and xray sounds like a rational approach. ugh, below the "ankle"
I second merrygoround's statement. Had a 4y/o TB gelding flex miserably, people passed on him. Second set of people vetted him and again he failed, they bought him for a discounted price. He is currently working and showing and has not shown any changes in his soundness etc. Have a wonderful mid teenaged pony that has not had any work done on her that is coming home r/t her not passing her flexions. She is a 3k pony with a great mind, safe and kind....needless to say I will be leasing her out instead of trying to sell her.
Flexions can absolutely be misleading... but they usually aren't. X-rays will help you assess the condition of the joints and determine if the issues are managable, or something that makes you want to pass.