I have seen sites in the past that restricting the modification of client seed, example: no more than one time per minute..
That could be great, but it needs to someone creat it and make it available for everyone.. but it still can there a issue here, they can put a script on the webpage for sniffing the seed.. a casino who is ready to manipulate the results would surely make this!
Instead, In the case of creating an open online tool, that provide a (external to the casino site) element that can be embedded in the game page in way to ensure that there's cannot be any alteration, there is a great odds that the tool became very quickly popular and so being largely adopted !