I am having the same issue (it always happens around 10-12 mins remaining):
An error occurred installing macOS.
You can try again to complete the installation.
I have reset the PRAM/NVRAM.
I have reset the SMC.
I have re-enlisted in the beta program.
I have re-installed the beta software.
and I have re-downloaded Big Sur install software
All with not avail...
MacBook Pro (15-inch, 2018) 2.9 GHz 6-Core Intel Core i9
32 GB 2400 MHz DDR4 Intel UHD Graphics 630 1536 MB
ravision
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