Until when can Ashkenazim eat kitniyot (legumes) on erev Pesach?

The Rishonim (Orchot Chaim) allow kitniyot until Pesach night itself and so writes the Pri Megadim, but many have the custom not to eat after the time of Chametz prohibition (about 10:10, which is also the custom in Jerusalem). This year there is additional reason to be lenient, for we must have pleasure on Shabbat, but because we can't eat matzah on erev Pesach, there's "not that much to eat". Apparently you personally don't know your family's custom so accordingly, surely you can be lenient this year and eat kitniyot on Shabbat until candle lighting.