What kind of cutting groove do you want? Easily discharge iron chips? Want a spring-shaped iron chip? How to deal with the oxide scale on the surface of the workpiece during rough turning? These problems are not just about broken grooves/inserts.
All aspects are connected! To deal with oxide scale, using a blade that is too good will be a waste, and a blade that is too poor will be easily damaged. For the time being, it is recommended to use YW1 or 2, which will be better than YT14/15...but it also depends on how well you sharpen your knife!