Orvanians had always feared using the Momentum Source to power their technology. This is because the Speed Source is something that seems to have its own Will.
It is this undying Will that have lit up an entire era of Speedsters roaming the entire multiverses in the ancient epoch.
And what is this undying Will is? It is the undying Wil of Asargan. The Will of this Etherna was so strong that even after his destruction, his Will were passed down
Even after his entire race was wiped out, his Will was undying and remains until today.
The Orvanian High Council fears that using such a force that has its own Will might backfire on them
It is not the first time that Orvanian had saw the adverse effect of using something with its own Will.
There were many such example in the Omniverse of such failure.
And anything concerning the Ethernas had always frightened the High Council. The experience with Sithulran had quite alarmed the High Elders.