Just saw this! Tsai Ing-wen is openly inviting DPP-sympathetic voters to give their at large votes the the TSU. I guess Tsai imagines that the party hardcore will stick with the DPP while "independents" might be attracted to Lee Teng-hui's part. More substantially, maybe she's hoping that if any one party breaks the 5% threshold, it better be the TSU.
Not sure how politically astute this suggestion is in the long run, but perhaps she's just throwing a dog a bone without any expectation that voters will change their minds and DPP strength will remain as strong as it could get anyway.
I'm a bit surprised and am not sure of the political implications, but quite pleased (emotionally) with this move.