Paul said we are surrounded by a “whole cloud of witnesses”. So rethink your statement again, the dead in Christ do have living consciousness. Christ had a living consciousness as he preached in Hell for the three days while his body lay dead in the tomb. The rich man had a consciousness of being in hell while noting that Lazarus was in the “Bosom of Abraham”.
Now your statements regarding time experienced by our spirits in God’s spiritual plane verses our temporal plane may have some merit but it is speculative. Paul spoke of these clouds of witnesses existing in the NOW(temporal) time. He didn’t say however that we were to try to talk to them; we were to be encouraged by their presence never the less!
The witnesses word in this use means “Martyr”. Whence Eng., “martyr,” one who bears “witness” by his death.
It does not imply a present tense consciousness, but a past tense. Of course the future tense of the resurrection is implied.
I have already explained the differences between the dead in Christ who SLEEP waiting for the Trump, and those in Hell now waiting for the great white throne judgment and those who WERE in Abraham’s bosom and are NOW conscience in Heaven.
As for talking to the dead, saved or unsaved, it is actually forbidden under penalty of death.
We are to be encouraged by their EXAMPLE.
They are NOT present.