This is resolved by Spectrum_10.03.00.PTF_10.3.027 for 10.3.0. PTF_027 does require D04a to be installed. This will also resolved inSpectrum_10.03.02.BMP_10.3.003 for 10.3.2 once released and will be included in 10.4 once released. The release notes show:
Symptom : SpectroSERVER performance problems, causing OC to red-box but not failover to secondary.
Resolution: Resolved several SpectroSERVER performance problems due to very high scale, and improved failover
mechanism to properly failover to secondary when the primary is in busy/hung state.