Hello from a New Zealand instructor. I am happy to spin a Cessna 152, great little beast, a 172 is harder to get in to a spin.
I wont spin a 150 horse 150 (150/150) , and NO WAY A PA38!
The 150/150 has a C of G change that makes it a little, shall we say, hard to recover, and I have had problems with recovery with a 152tailwheel conversion.
Instructors here must do a 1 hr spinning lesson b4 they get an
instructor rating, but not many get an endorsement to teach spinning. It is safe when do correctly(even fun) with a well maintained C152 Aerobat.