That is an extremely important question. The biggest problem is indeed access to those credits and the fact that they depend on tax auditors' assessment of the R & D program. They determine whether the R & D activities you have initiated are deemed acceptable.
A corporation that establishes an R & D program has no certainty that the activities it has undertaken will make it eligible for tax credits. Furthermore, it receives those tax credits after it has done its R & D. So, there is clearly an issue in terms of the cash assets needed to fund any R & D activities. Larger scale or riskier projects are often carried out in partnership with other corporations. New companies are set up to undertake those activities and potentially introduce products into the market. That means these companies do not pay taxes. It takes them years to become profitable, so they cannot access those tax credits.