Having recently done a level 7 qualification the advice was you should really wait at least a year between assessments, however there are some that can be repeated after 6 months e.g. spelling.
Some EP reports are not written well when paid for privately, so I can see where your assessor is coming from on that point. Crucially the AA criteria from JCQ states if your are going to use an EP report as evidence then the EP must have a working relationship with the school and must have had a copy of the form 8 before doing their assessment, was this the case? If so, you can use EP standard scores to apply for AA as long as they used assessments on the JCQ approved list. If not, just wait for Feb 24 when they are in Year 10 and get them screened at school. Take copies of any mock papers they complete before then without AA as evidence to show they do need extra time/reader/scribe/ which ever arrangement you are after. Wouldn’t useful to highlight missed questions and also get feedback from teachers as to classwork vs tests.