I think it doesn't matter as long as you demonstrate your evidence/argument clearly.
Other letters of support were ted from researchers who never worked with petitioner; However, it appears that the references by the authors were from reviewing the petitioner's resume or much-cited publications or praise from other researchers. These general assertions represent claims rather than evidence. The authors have not claimed that their research is a result of the petitioner's research or that they have applied any of the petitioner's research to their own.
Can you find any citation from the their papers?
I am also preparing for my appeal, we share our ideas.
My email: collin.ho@gmail.com