Shared Portfolios have out of date info
Title shows "As of May 02, 2019 but data is actually all from 0430. When should this update?

Usually, it is showing the EOD date. Since 1st May is not trading day for SGX, it can be delayed.

Since it was May 2, I was wondering what time of day updates are processed.

If I remember correctly, it should be after EOD data have been released. That is, it should happen within 1-2 hours after you receive daily email (for SGX). However, for those with US stocks, it would still reflect previous day because US date is one day slower and I remember I display the earlier date whenever user have multiple exchanges in portfolio.