agreed.
but one exception, and it's not really pertinent to your fluid level issue.
FYI,
do not flush the trans. causes more issues on some trans than it *tries* to solve.
the idea is flushing out particulate matter. if particulate matter is trapped behind a seal or pump, to flush that, the seals would have to be bad. leaking in the first place. if particles came from a component behind a seal, then flushing may force it past the seal. compromising the seal. it can get micro cuts. like what maybe sand paper would do to a seal.
only way to get the results a flush job *tries* to accomplish, is to dis-assemble, tear down, clean, inspect. and a flush job will not flush a converter. it has a large volume low spot. can't be flushed.
and all that will cost more than a re-manned trans.