Page rendering breaks when using BlockList in Single Item mode

[greystate]

When NestingContently goes through the items in a BlockList to see if they should be removed from the renderable list, it assumes that it returns a BlockListModel - but a BlockList in "Single block mode" returns a BlockListItem<> so the PropertyValueConverter throws an exception which prevents the page from rendering.

It chokes on this line because it can't cast from BlockListItem<T> to BlockListModel:

NestingContently/src/NestingContently.Umbraco/Editor/NestingContentlyBlockListPropertyValueConverter.cs

Line 28 in 2adcf31

var model = (BlockListModel?)base.ConvertIntermediateToObject(owner, propertyType, referenceCacheLevel, inter, preview);

In effect, when NestingContently is installed, it's not possible to use the BlockList Editor in "Single block mode"...