First SOLO and First SOLO crosssountry flights must be authorised and supervised by an FI.
All other solo flights can be supervised by an FI(R).
In the course of a PPL course, leaving out the first solo and first solo crosscountry flights, a student will complete some 5 to 10 or more solo flights. Thus, taking one student through the course will gain an FI(R) the required instruction and 10 of the minimum solo supervisions.
IMHO, if it is so difficult to achieve the required number of solos, the options are to a) remain an FI(R) because with so few students, there is no need for another FI or b) Go elswhere an find more students.
My reading of kissmysquirrel's post whas that he claimed flights which were being supervised by an FI as being supervised by himself. I don't think that is legal.
A far better way of bending the rules are to send a student off on a circuit detail and get than to make " four 15 minute flights during the hour".......they enter the four solo flights in their log book, and you record four supervised flights towards the 25. All totally legal and within the rules.
Perhaps doing the latter will rapidly increase the umber of supervised flights