For example I have heard that hours spent learning with BGA clubs that offer NPPL SLMG / TMG training cant be counted towards the JAR (EASA?) PPL.
JAA licences require JAA syllabus instruction with CAA/JAA instructors. The Motor Glider Club at Hinton is one of the very few places in the country that can give combined SLMG/CAA instruction; you can find SLMG instructors at gliding clubs who are also CAA instructors but most are BGA motorglider instructors who have done an NPPL SLMG instructor's course.
SLMG training at BGA clubs will count towards an EASA licence. An NPPL SLMG will become an LAPL(A), TMGs only. You can add an SSEA to your NPPL pre EASA conversion, or add SEP privileges to your EASA LAPL(A) post conversion. You will be able to turn an LAPL into a PPL.
It's quite amazing the number of clubs that don't seem to offer NPPL courses or recognise that there are glider pilots who want to take advantage of the 10hrs instruction needed (yes I know that's a minimum) to get the chance to fly things with fans on the front too.
Most BGA clubs don't have a TMG & only the biggest & busiest have enough customers to keep an SLMG instructor current. Lasham, Dunstable & Bicester all offer SLMG instruction in your area, possibly RAFGSA Chilterns at Halton as well.