The Meek algorithm for counting single transferable votes (STVs) is considered, at least [[ http://www.openstv.org/faq | by some ]], to be the best vote counting algorithm when electing multiple people and simplicity is not important. [[ https://en.wikipedia.org/wiki/Counting_single_transferable_votes#Meek | The algorithm ]] does not seem to be computationally too intensive.
Enabling this in SecurePoll should not be hard; the voting interface is exactly the same as the [[ https://en.wikipedia.org/wiki/Schulze_method | Schulze method ]], which is already implemented in SecurePoll. It is only the tallying mechanism that is different.
Please consider adding this to SecurePoll as an option.