Permitted Work is frequently approved. The whole point of PW is to allow people to test the waters when it comes to working without fearing that they might lose their benefits if they find they can't manage. Volunteering is almost never rejected.

The caution will more than likely appear on an "Enhanced" disclosure. That said, most employers can't use the "enhanced" option unless you're dealing with vulnerable people, (teaching, care homes, police, NHS etc) or in an area of high security (MI5/SOCA, HMCS, Prisons, Airports, Military etc). If it's just a standard disclosure, the records won't be included. What's the company, or at the very least, the job description?

Its worth noting that so called "charities " such as Stepchange cover their overheads by getting paid a percentage of what they collect. Its in their interest to get as much out of you as possible, they are simply agents of the whole sordid debt collection industry with a nice glossy front to entice you in. My advice to anyone thinking of using a DMP company is dont ! Do it yourself, I wish I had and have learnt the hard way.