Severe Disablement Allowance & Supported Permitted Work

I work for an employment project, supporting people with disabilities back into education, training or work. Alot of our clients are receiving Income Support or Incapacity Benefit which is straight forward regarding SPW - working less than 16 hrs, £20.00 earnings disregard or £95.00.
I was hoping someone could confirm what SPW someone in receipt of SDA can do, if they can do it at all?
From what I have read online & in the CPAG handbook, SDA is treated the same as IS for SPW but I wanted to see if anyone else had had any experience of clients on SDA undertaking SPW?

Many thanks.

I have no direct experience with SDA and SPW. However, my understanding is that PW under SDA has the same rules as IB, not IS. Pg 858 of CPAG discusses both IB and SDA.