“Of course, more than 10% ends up merging in, significantly delaying the rest.”
This is incorrect.
The way you describe is very inefficent and causes traffic.
bot h lanes should be utilized until the end then merge in an alternating fashion
This has been studied over and over
See for example “EVALUATION OF THE LATE MERGE WORK ZONE TRAFFIC CONTROL STRATEGY ”
or “Dynamic Late Merge Control Concept for Work Zones on Rural Freeways”
so to answer your question
“which one would you choose or any better suggestions?”
There is a clear better suggestion. stay in your lane and merge at the last minute better for you, AND better for society. The rare win win.