The verb prefix en- seems redundant to me. For example
- a book titled ‘Something’
- a book entitled ‘Something’
Are these identical in meaning, or is there some nuance?
Sometimes en- is redundant, and sometimes not. Also, redundancy is not always a bad thing.
There are fairly large differences in meaning between force(d) and enforce(d), treat(ed) and entreat(ed), trust(ed) and entrust(ed), fold(ed) and enfold(ed).
There is a previous question about the usage of title(d) and entitle(d) that you may want to look at: When is it appropriate to use "titled" vs. "entitled"? In the context of your example, either could be used with no difference in meaning.