Hi eugrus,
That’s not actually an issue, for now maximum number of LingQs you can export at once is 200.
Unfortunately it’s not quite as simple as upping the number from 200 to unlimited, as our server was regularly timing out when trying to fulfill these export request.
At some point we would definitely like to do this, though in the meantime you may be best off just spending an hour or so every 3 months exporting your LingQs - or even just sorting by Creation Date and exporting the newly created ones, if that works for you.
The most common solution to provide for data portability while not overburdening servers is limiting full backup to once a month or so for each user.
As LingQ is a company also targeted at the EU market, providing your clients with technical ability to download the full amount of their data in a structured machine-readable form is something you are going to be obliged to comply with under the GDPR with effect from 2018, which is also going to be enforceable in Canada under CETA.