That is exactly what I mean by PON, too.
However, with a few tweaks. (You mention two figures for PON ... 128 and 32).
The regs around planning for a PON, or 'Spliiter Node' if you prefer, is 120 THP (Total homes passed). Each SASA is planned for 30 THP, but there is capacity for 32 as you say .... however, that requires managers authorisation to add one further THP, and his managers approval to take the last one ... so most jobs are planned to the 30 THP.
Yes, there are different power optics such as B+ or C+, but these are optimised based on distance rather than THP.