User blog comment:Gyoretsu/Limit Breaker mechanics?/@comment-26432452-20190105075758

Mechanics? If you mean the limit breaker that you would get by exchanging 50 sphere then nope, no limitation on that.

FYI, I've bought 4 LB cards already. Used once on Shuza v3 (lv 70->75), twice on Kushan & Shishan (lv 60->70), and once on Riveira v3 (lv 65->70).