Just watched that video you posted mate .... it could be me getting old , but there very young lads to be taking line advice from 😆. But even they opted for the 18lb which is still low diameter for 18lb ( same as the 15lb I use ) . It will be fine where no snags or weed are an issue . Just looking at the range it looks to be aimed at fishing long where leader bans are in place & weed & abrasion aren't an issue. I've used similar lines in the past so talk from experience & lost fish !! The 18lb could be interesting for level line casting & giving it the beans, could be worth a test in the future.