PSReadLine is a major advance for me. I use bck-i-search very frequently to search and invoke commands from my history (Ctrl-R in any modern powershell console).
However, it is not supported, and will not import, in ISE. (See: PowerShell/PSReadLine#401)
I still use ISE because it's great for debugging and quick edits, so: this is my approximate implementation of bck-i-search for ISE.
Run this command, e.g. in your profile:
Register-PSISEReadlineShortcutThis adds Ctrl-E as a keyboard shortcut. (Ctrl-R is taken already.)
Hitting Ctrl-E will start bck-i-search. You can enter a substring and use tab-completion to search back in your command history. When you press Enter, the commandline will be invoked.