All of TR's pillars come as standard with undercut or non standard without undercut. The advantages of undercut are that there is no need for washers in assembly and they offer a flush fit. This data sheet details the range of materials and sizes the spacers and pillars are available in.
Comment: The UK is closer to deindustrialisation than reindustrialisation
"..have been years in the making" and are embedded in the actors - thus making it difficult for UK industry to move on and develop and apply...