Cleveland line extension would not be fast or direct enough unfortunately.
The Cleveland line takes about 1 hour from Roma St to Cleveland. If this line was extended to Victoria Pt, it would take even longer, giving a journey time similar to the direct bus while also not servicing Capalaba, Carindale and the Old Cleveland Rd corridor.
LRT would incur the cost of busway conversion, cannot cross the Victoria Bridge (weight limit) or handle the gradient or curves in QSBS (and likely Adelaide St tunnel). In contrast, the heavy rail option already has access via the Merivale Bridge in this section.
Redlands, like many LGAs immediately outside of BCC has very poor PT and very poor mode share.