What's important is if they are a TDE type competitor and the data stays encrypted in flight or if it simply stores the data encrypted but decrypts for backup?
Either way, LiteSpeed will work, but the latter will allow for compression whereas TDE style encryption does not allow for compression.
In the TDE style case use LiteSpeed at compression level 0 since there's no reason to waste CPU cycles trying to compress data that can't be compressed. Be aware that enabling encryption will impact the backup size and should be tested to see exactly what the impact would be.
We suggest, checking with NetLib to ask about the differences between their encryption model and Native Microsoft TDE? Also, check with them about if they have an info as well about interacting with other third party backup tools.
In our testing, enabling TDE negates the compression of LiteSpeed. The LiteSpeed backup is going to be the same size as the Native backup on a TDE enabled database. The following post has good information as well.