Why not change the BCG protocol to lower strength?

I posted the following question to 'Ask Dr. Lamm':

If there is evidence that a reduced BCG dosage strength may
improve efficacy, why isn't the protocol changed to start with reduced
dosage strength. Seems like fewer people would fail BCG treatment (I
failed and had a RC upon recurrence of only CIS) if the dose was lower.
Maybe a rat study is warranted on the lower dosage strength?

Here is his response:

There is a lot of work that has been done, both in animal models and
clinical trials. BCG is now so effective that it takes thousands of
patients to demonstrate that something new is superior. Hard to get
funding for reduced dose BCG studies. See my work with Reichert regarding
dose response in animals.
Don Lamm, MD