Only if you ignore calculations around quantum collapses, or whatever your favorite interpretation calls those. We don't yet know how to calculate when those will happen, so that is by far the most complex task since it hasn't been solved yet.
I suspect that solving those collapses is key to connecting quantum mechanics to relativity, seems like a much more reasonable place to look than to invent even more fields like string theory does.
Well, there are no experiments that have been done or even suggested that requires this. Except maybe the Wigner's Friend thought-experiments? They seem pretty interesting and strikes to the center of the evolution discontinuities issues.
But for all normal practical purposes you don't need to solve that and can ignore it (which is both a blessing and a curse of course)
I suspect that solving those collapses is key to connecting quantum mechanics to relativity, seems like a much more reasonable place to look than to invent even more fields like string theory does.