Edit: Since writing this post I have come to read more on the subject and in the Help:Alternative Sources page at Wikitree and I have discovered that the use of Span links "... is not ideal and is not generally recommended for manually-created sources. It is supported because it has to be. We may be able to find a way to fix this in the future."
Based on this information, I will not be using span links on profiles and will edit out those that I have created. For research notes, I will try to incorporate them as a note within the source, for example:
Jones, Michael. "Quaker records 1800-1840." Cleveland, OH: Jones Publishing, 1984. p. 147. Note: As indicated in his forward, Jones only includes Quaker records from 4 counties.
Note: The records only cover 4 counties as cited at: Jones, Michael. "Quaker records 1800-1840." Cleveland, OH: Jones Publishing, 1984. p. 147.
For those that don't have a source to migrate into or are too long and need to be put into the research notes, I will merely add a mark that is not linked such as [a] or [i] or an asterisk and include a note below the text:
Blah blah blah.*
* Explanation of blah blah blah.