Brett beer and cider questions

I have two vials of Brett. C. and I would like to toss one in a gallon of unfiltered pasteurized cider and use the other to make one gallon of beer. I figured I won't need a starter for these small batches. Both will be 100% Brett C. brews. My questions are can I just ferment the cider in the glass jug it comes in or do I need some head space for the krausen? Also for the beer recipe do I need to use acidulated malt or flaked oats? I came across some recipes for 100% brett beers and they seem to always include these. Thanks

You will get little to no kraeusen in cider. so just take out a few ozs and you will be fine.

You don't need oats or acid malt for the beer. Yes, brett prefers lower ph wort, which is why the acid malt is in there, but it will be fine without it. I don't know what the oats do that would be critical for the brett.