Hi, Misha! It turns out not only you wanted such an opportunity...
A very convenient solution has appeared recently. The function "Return to the old interface" is available with free Interface Switcher — a tool that allows using of both interfaces. So it is not exactly the return, you'll get the ability to combine them.
The tool can be installed / uninstalled in 2 minutes. It does not impact entity records anyhow and needs no reboot.
You may try it and leave your opinion here:
uds.systems/.../interface-switcher
Hope I helped you a little with solving the problem =)