When import a external CSR to sign via the eDir-CA, iManager should check the CSR. If it is not able to issue a correct certificate (e.g. if the key lenght of the CSR and the max. possible lenght of the CA is not matching) iManager should display a warning insteed of serving a corrupt certificate without any comment.
Just now you can import a CSR with 4096bit via iManager to sign from the CA. Then you get an certificate to DL without any comment. But if you check this certificate it is not useable.