The only feedback I have here is to possibly integrate an exercise or challenge using an external regex tester in Episode 10.
In addition to the reference sheets that are linked, I suggest linking to a live tester like Regexstorm: http://regexstorm.net/tester. You could also consider adding a challenge to this Episode that uses this tester, or use it to demonstrate the construction of a more complicated regular expression like the one in the find and replace checklist. Happy to help with this if it's of interest!
The Find and Replace checklist "Add a space between 090 class and subclass" should be updated since the field in the lesson data is an 099. Also, in step 4, the expression (=090 \\$a[A-Z]+)(\d.) should have two spaces after 099 (one seems to have been deleted accidentally); so it should be (=099 \\$a[A-Z]+)(\d.)
How could the content be improved?
The only feedback I have here is to possibly integrate an exercise or challenge using an external regex tester in Episode 10.
Episode 10: