cl-test-grid tests are running and results started to come. This diff compares results of when ASDF 3.1.7.43 is uses vs the ASDF deployed with each particular implementation: https://common-lisp.net/project/cl-test-grid/asdf/asdf-diff-51.html
I haven't analyzed them, but there are some failures you might be interested in, like Undefined function ASDF/INTERFACE::OPERATION-FORCED called with arguments (#<LOAD-OP>) . or ASDF/FIND-SYSTEM:FORMATTED-SYSTEM-DEFINITION-ERROR : OPERATION instances must only be created through MAKE-OPERATION.