I had had pretty much the same thought. But I think that would also increase the rate significantly.
"...But I think that would also increase the rate significantly...."
I'm not so sure. If we acknowledge that the rate is going to remain fixed for year one, and look at this as a newly forming entity would "organizational costs," then we can amortize the debt incurred to fund this outlay over some period of time. I wouldn't advocate paying this 'expense' off in year one. I'd amortize it over several years and that should have minimal effect on the rate.
My concern is that IF the price of goods drop as some think they will (precipitously), then adding to the prebate unnecessarily would be an inflationary policy. It's hard to quantify how much new capital will flow into the US as a result of removing the corporate tax. I think the danger of increasing the prebate in combination with an influx of new capital is that we'll significantly fan the flames of inflation. This is tricky business.....