I have an example from my non-VMS research of crosses being drawn above the names. I agree with everyone in the thread who is saying that it's much more common to find crosses preceding the name, but I wanted to share that I have seen a few crosses over holy names. I don't think I have ever seen crosses separating the syllables of holy names, but I would not be at all surprised if someone was able to find an example of that somewhere.
The image that I'm sharing is from an English or Welsh manuscript written c. 1100-ish. The main text of the manuscript is John the Deacon's
Life of Gregory the Great, but the final few leaves have some medical recipes. The picture is of a page with several medical prayers and medical recipes - the first is for women in childbirth and in the fourth line you can see the crosses above the text.
Please excuse the terrible quality of the picture - this was only meant to be a private research shot to allow me to triple-check the text. I haven't written the name of the manuscript in this post as I'm not quite sure whether sharing it on a forum is in accordance with the library's photography policy and I would prefer it if this didn't pop up in a casual google, but if you can read my note in the top corner you'll be able to see the shelfmark. The manuscript has not been digitised; there is a description online, but it's based on a description from the 1850s which incorrectly says that the manuscript is from the 10th century.