In A Brief History of Time, Stephen Hawking said there are no boundaries or singularities in imaginary time. I know Wick rotation is regarded as mathematical convenience or trickery. But Max Planck thought of his idea of quanta as a math convenience. And Albert Einstein seems to have developed the photoelectric effect's explanation from Planck's quanta. So could Wick rotation also end up having practical application, with our so-called real time existing on the X-axis and imaginary time on the y-axis. In that case, would the lack of boundaries and singularities mean the universe has no beginning or end? The relevance of imaginary numbers to the cosmos is that complex numbers have uses in quantum field theory, special and general relativity, and spinors.
Real time and real numbers are still present, so we can't get rid of an initial singularity through a Wick rotation. This reflects the fact that Wick rotation isn't so useful in General Relativity. But Einstein's theory, though the best theory we have of gravity and the universe, is incomplete. It needs to be combined with quantum physics. In such a theory of quantum gravity, it's possible that Wick rotation is extremely useful, just as it's a very useful mathematical technique in quantum field theory. We don't live in a universe that is merely real (governed by real numbers) or exclusively imaginary but is complex, embodying a union of real plus imaginary. Then Wick rotation means there could be an additional time dimension - time and space are inseparable, so another space dimension also exists - as California Prof. Itzhak Bars has said (https://phys.org/news/2007-05-two-time-universe-physicist-explores-dimension.html). Just as E=mc^2 describes energy producing mass in known space-time, dark energy might not be the cause of alleged cosmic expansion but could account for the formation of dark matter. Thanks to astrophysicist Ethan Siegel for inspiring this paragraph.