I've used both Spelt malt and Spelt flakes in beer. Mostly in Saisons, Bier de gardes and Wit biers but I have used them in place of wheat malt and wheat flakes in pale ales too.
Spelt tends to be a bit more grainy than wheat but it still lightens beer body and colour.
It's easier to use flakes as they already glutenised and won't gum up a mash in large quantities. Although, spelt malt itself has a glutenisation temp of 61C so it can be mashed in without any lower temp rests.
German homebrewers due use it Hefe's where it is described as "that spelt taste"...historically a lot of Roman beer was brewed with spelt and there is a history of spelt beer in Ireland.
The Malt Miller (one of the forum sponsors) can supply both types.
Best beer I have brewed was a Pale Ale that was a equal quantitities of mild ale/spelt/pale malts.
F