FWIW, infinities could go either way if you recognize moral goods that can aggregate by summing. I think where infinities seem more likely for suffering than goods are if your views are ethically asymmetric and assign more weight to suffering, especially some kinds of suffering being infinitely bad, but no goods being infinitely good (or no goods at all), or goods only being able to offset but not outweigh bads.
FWIW, infinities could go either way if you recognize moral goods that can aggregate by summing. I think where infinities seem more likely for suffering than goods are if your views are ethically asymmetric and assign more weight to suffering, especially some kinds of suffering being infinitely bad, but no goods being infinitely good (or no goods at all), or goods only being able to offset but not outweigh bads.