I think it would be very difficult for Lingq to add a high-quality converter in the near future. The first 99% of Traditional <-> Simplified conversion is pretty easy, but the last 1% is difficult. There are various issues.

Although conversion is not available within Lingq today, you still might be able to do what you want to do. As a Lingq user, you can use the (upper-right three dots menu) "Print Lesson" button, together with Copy-And-Paste and an external program such as Microsoft Word, to create a file that contains the text of a Traditional Chinese lesson. You could use conversion software outside Lingq to create a Simplified Chinese file from that Traditional Chinese file. At that point, you would have a Simplified version of the text to refer to while studying from the lesson in the Traditional Chinese part of Lingq. If you want to go further, you could visit the Simplified Chinese part of Lingq and use "Import Lesson" to import your new Simplified Chinese file as a new lesson. You could edit that Simplified Chinese lesson to add the original video.

Of course, your Lingqs and known words in the Simplified Chinese part of Lingq are separate from your LIngqs and known words in the Traditional Chinese part of Lingq.

If you have purchased Microsoft 365 software, you might be interested in reading https://answers.microsoft.com/en-us/msoffice/forum/all/in-ms-365-word-how-to-convert-traditional-chinese/f46cdf06-f404-429a-86cb-74f4d8bfb114

We'll see what we can do about it, but it's unlikely that it will be implemented in the near future.