If you check the Git repo for the plugin you will find that it is maintained with updates as recently as October, and it works fine on 3.10…I’ve noticed Catalyst tends to forgo updating the official Moodle plugins page for some of their more IT/enterprise focused projects https://github.com/catalyst/moodle-fileconverter_librelambda

Are you referring to this plugin:
https://moodle.org/plugins/pluginversions.php?plugin=fileconverter_librelambda
As you say, it’s only available for Moodle versions 3.5.and 3.6.
The plugin hasn’t been updated since Sunday, March 31, 2019.
Given that Moodle 3.9 is now the current release, and work towards Moodle 4.0 is under way, my gut instinct is that this plugin may no longer be updated.

It’s an interesting point.
Disclaimer: I don’t like Google – I don’t like their licensing, and their marketing machine that seems to convince everyone they are the saviour of the internet, which they definitely are not.
However, there is a continuum, between security and ease, and sadly many schools for example will happily encourage their students to “buy into” the Googleverse and Microsoftverse, with little of zero ethical consideration as to what this means.
However, a Google Docs service provides a similar service to a MacD9nalds when you are hungry – it’s fast, cheap, and easy, and we (mostly) ignore the fact it’s unhealthy.

Hi Oscar, I’m not sure how you would be able to do this….there might be a way if you are clever enough with MySQL queries. If you can find a list of the file IDs you want to delete, you can use Moosh to purge them: https://moosh-online.com/commands/

Hi Oscar, I didn’t find a way to do this. If you want to keep unneeded files from being converted into PDFs you can disable the Scheduled Task “Prepare Submissions for Annotation.” However, that would mean that any graders who are using PDF annotation would have to wait for the files to convert when they visit the assignment grading screen. and this can be undesirable. You may just want to look at disabling the Annotate PDF Feedback plugin altogether if your server can’t handle the space.