Sometimes I wonder at this point if we are better off just trying to run stuff in traffic and create an impetus to provide this infrastructure after the fact
The reality is the timetable can be adjusted to reflect the travel time, and even though it’s not perfect people will learn what bus they need to catch to make the connection well
While I personally do want to see better connections between Beenleigh and Loganholme, I don’t think the 555 is the right service to do it.
To be perfectly blunt, I don’t think it is fair for capacity on the 555 to be used up by Beenleigh commuters who also have the option of two train lines into the city (an extended 555 would take about the same time to get to its Queen Street terminus as the Express takes to get to Central).
For passengers at Loganholme, Springwood and Rochedale, the 555 is their main service to/from the city for much of the day, and their only peak hour service that goes via South Bank. It is a service that does suffer from peak hour capacity crunches as it is, with AM 555s almost always being at standing room only by the time they hit Rochedale.
If you want a better connection between Beenleigh and the SE Busway (that isn’t via Altandi) I would recommend a short running route between Beenleigh and either 8 Mile Plains, or maybe Griffith if you want to stretch it to service Garden City, where passengers could then transfer to the M1 to continue their journey, without negatively impacting the 555.