Hi John,
The chippings will take nitrogen from the soil ONLY if you dig them in.
Use them as a mulch. I never add them to the compost bin as they will rob nitrogen and slow the general decomposition process by so doing. In saying that I have enough twiggy material in my heap from other additions.
BTW. I looked through your Photo Albums and I must say the way you have transformed that site is amazing.
Don.