This would certainly seem like a fairly simple cost-effective solution.
In many of our provinces we have a private adoption system as well as a public adoption system, which is a huge benefit to the province. When they're able to, families who are motivated and interested in adoption will cover the costs by having private adoption professionals do their home study, attend private training programs, and cover some of the costs.
The actual costs can't be done as a tax benefit until the year they adopt, which could be several years later. It seems reasonable that as an incentive to families to consider becoming ready to adopt—because we need them more than they need us—this would make it more reflective of the actual amount families fund out and allow them to do it in the year they incur those costs. I think that would be a huge benefit.