That is definitely an improvement, but I find that concern a bit exaggerated.
If all you need is unpredictability, a minor bias is sub-optimal but not disastrous. The 256 % 62 bias used here should reduce the min-entropy per character by 5%. And you can easily minimize the bias by using larger integer than a single 8-bit byte. There few algorithms where minor biases cause a disaster, like DSA.
If all you need is unpredictability, a minor bias is sub-optimal but not disastrous. The 256 % 62 bias used here should reduce the min-entropy per character by 5%. And you can easily minimize the bias by using larger integer than a single 8-bit byte. There few algorithms where minor biases cause a disaster, like DSA.