Indeed most of the services practicing jump bus have irregular
frequency. Just like svc 36 is another example having many chances
of bunching and overcrowding. Even svc 124, last sat at about
7.45pm at Eunos having buses bunching together and of cost the bus
is crowded. There are pros and cons u see.
I believe you're not acquainted with jumpbus practices, but
still will want to jump to conclusions. It's really disappointing
that you shoot without checking your facts.
Service 36 is a very unique jumpbus service, where the headway
is entirely controlled by the running time, with an additional 2
minutes of vehicle layover at PTB2 at the end of the trips. The
service is so unique, even the drivers' mealbreaks and layovers are
non-standard, and they are entitled to longer mealbreaks anyway to
compensate for the distance they have to walk in to have their
meals.
There are only 4 other services whose headway is tied to the
running time due to vehicle layover constraints.
As for the observation that Service 124 being late, the reason
cannot be due to jumpbus, because most drivers do not "jump" to
another bus except during mealbreaks, unless the headway is very
small. Even Service 162M drivers always return to Yio Chu Kang
Terminal late in the post-PM peak, but they don't take another bus
out, you know?