Grandpa's (now my) banjo-mandolin dates to around WWI and my Varsity banjo-uke isn't much newer, if at all. I can't swear to the banjo-uke's usage history but I know the banjo-mandolin's strings (much higher tension that the banjo-uke's) haven't been loosened much in the last century and the head seems to be in great shape. So no, don't worry about what low-tension strings will do. If my banjo-uke had tuning machines instead of tension pegs I'd even consider loading steel strings onto it.