I share the pain you are facing with bitcoin tx fees. However as litecoin usage and price increase don’t you think tx fee there will increase also. Also if you are looking at user base, already bitcoin has a small enough number of users. I don’t think even million people worldwide would have litecoin wallets.
Would be it possible for you to accept bitcoin in user interface and internally do to transactions on litecoin chain ? This way you can still take advantage of the bitcoin user base