Use stratum also for decred.
Replace -dpool http://dcr.suprnova.cc:9112 with -dpool stratum+tcp://dcr.suprnova.cc:2252
The rejects will drop to 1-3%
And You have to wait for almost 24h for DCR confirmation.
For me, the use of suprnova stratum for DCR, combined with -dcri 20 resulted in a rejection rate lower than 1%
