According to the ORR, a 'new' (to this country anyway) track machine has been authorised for use on HS1, on behalf of Swietelsky. It's numbered 99 81 9125 018-7, and the information provided is that it's a 'BDS 2000-4 Ballast Distribution System' machine. Presumably it's similar to 99 80 9125 002-2 listed on the website. Something to add onto the website perhaps?
New track machine authorised for HS1 use - On-Track Machines - Forum
New track machine authorised for HS1 use
Also, in addition to the above, authorisation has also been granted for 99 80 9123 004-0, for the same operator, also on HS1. This one is a 09-32x-4x4/4s Universal Dynamic Tamper.