First I would like to congratulate the faucet team, it seems to me that after several attempts, finally found the way to successfully control abuse via backend.
But since they chose to keep the current difficulty of captcha, instead of diminishing and using a safe and dynamic virtual keyboard.
I have one more one recommendation to make the faucet more friendly to humans.
Instead of using:
"BCDEGKMNPQUVXY36789"

Could modify to:
"BCDEFGRSQTVWXZ16789"

This would allow the use of the numerical keyboard, making it friendlier for those who do not have much experience typing, making the faucet more comfortable, since it will not need big displacements reducing the physical effort of the hands.


I still consider the mix of claims from the previous round to the new one, something that needs to be changed, with pauses for payments.
Currently the claims of the previous rank, and the payment has a delay of 15 - 20 min, which makes the beginning of the new round a part of the last.

The pauses would still allow greater control over the rise and fall of the "Threshold", which can rise exponentially in cases of new abuse.

As soon as the "Threshold" has a controlled value, it could be scheduled. Per example: 100blocks or 1000blocks
This would increase the Threshold's flexibility, which is based on an automatic average on rank.

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Now about the source of the raiblocks and their constantly reported problems, I believe you need to take a new path.

There are many included dependencies that are outdated for at least 2 years.
Updates are performed to correct faults, and if you wish to use external modules in your codes, you must follow the updates and their codes.
This will allow for greater flexibility in future versions of your client.

I strongly recommend not to edit external modules, but to create an internal module that can work with the external module, without having to move the rest of the code. Changing only the communication modules between A and B.