Think about what finding nothing does tell you, though:
There’s no purpose in considering repeating hock injections
There no need to repeat a lameness or neuro exam for these issues
There’s no need to repeat an EPM or Lyme titer
You get confirmation that your local vet isn’t missing something
While “we’re not really seeing much” are definitely shit words to hear, it really does a lot to inform and confirm. I would guess you’ve already spent a lot more than $1700 on this? Does spending this money at the referral clinic put some of these concerns to bed for you, if nothing really notable is found? There really is power, and value, in additional opinions.