UK did report this kind of problem several times, on Ergo Lite and on S-Ergo 115. From my records, this is the first time that UK reported the tyres of Sparrow (SM-150) have been sheared off.
For the Ergo Lite, originally they don't have alu. brake block (pad), we do run ECN to have alu. brake block on Ergo Lite for UK's orders. (Orders for the other customers are still without brake block.)
As regard to the S-Ergo 115, the standard spec are with brake block already but UK had ever reported the tyres sheared off.... Therefore, I am not sure whether it's a best solution to add brake block onto SM-150s (Sparrow), since SM-150 is a basic wheelchair.