If I leave out the barley malt, with the flavor or texture of the finished biscuits be dramatically changed? I just don't have any, and don't feel like going hunting.
I think they will be just fine. The barley malt syrup is a sweetener, and the recipe only calls for 1 T. You could substitute another sweetener like honey or agave syrup, I suspect, with good results.
I thought honey would be fine, but I used to try to used barley malt powder, and it always ended up changing the texture of the batter, like it somehow required massive amounts of liquid or something. I didn't know if that was a quality of barley malt in general, or just the powder.
I realize you don't want to go on the hunt, but if anyone is interested you can find it at a local home-brew supply shop!
I'd probably sub with molasses as the flavor will be similar.
Last year I was determined to make Malt Bread when I couldn't find it in any local bakeries. The quantities that a home-brew shop sold were enormous compared to what I needed and could store. I ended up finding jars of barley malt syrup in Whole Foods, various health food, and bulk stores. The product line they all carry is Eden...just in case you do decide to hunt it down.