Thank you for the words of encouragement, Alain, Luuttuaja, and Bert! For the fourth string, I'm currently using a Savarez 97 which has some intonation issues, but the tension is quite good. The previous Boston Catlines 4th string was really fat and floppy and wouldn't project at all. I've tried the wound 4th that you use, but my right hand was getting too confused on hitting the right strings (too much influence from having the 4th course not wound on baroque lute). I have Seagar Premier 1.05 mm fluorocarbon arriving this week that I'll try out which I've heard has excellent intonation. It will have about 15 pounds of tension tuned to F at 415Hz.