I know about struggles with upgrades between major Acumatica versions. Even regular minor updates sometimes bring the pain.
So I was thinking, one does spend so much on testing and acceptance, on troubleshooting and fixes, I bet it just never pays off, whoever you are - either a VAR or an ISV.
Maybe there is a way to cut it by doing automated tests? Basic or advanced tests that cover most critical business scenarios. It does sound quite simple yet challenging.
How do you get through upgrades? Do you have any automated acceptance testing in your company?
Maybe there are developers who could do it for a fair dollar?