We tested using 24.1 version and output PDF size was around 11MB. Can you please try with the latest version and share the file with us that you obtained at your side?
I just tested with 24.1 and can confirm, that the resulting file is around 11MB. Unfortunately that is still a lot bigger than expected.
Further testing showed, that direct PDF/A compliant conversion of the source word document from within ms word or with aspose word to pdf transformation results in a much smaller resulting pdf file.
We have opened the following new ticket(s) in our internal issue tracking system and will deliver their fixes according to the terms mentioned in Free Support Policies.
Issue ID(s): PDFJAVA-43581
You can obtain Paid Support Services if you need support on a priority basis, along with the direct access to our Paid Support management team.
We are afraid that the earlier logged ticket has not been yet resolved due to other pending issues in the queue. We will let you know as soon as we make some progress towards it resolution. Please be patient and spare us some time.