Correct.
"Nikon SLR cameras (without built-in adjustable eyepiece correction) have a base diopter value of minus one.
Standard eyepieces supplied with Nikon SLR cameras have no corrective value and are for dust protection only.
No combination of the camera’s base value of minus one and a given accessory diopter’s value is required to arrive at the final desired value. In other words, if you require a diopter of plus 3, simply add a plus 3 diopter to your camera.
Neutral correction eyepieces do not replace the supplied standard eyepiece. The use of a neutral correction eyepiece will change the diopter value of the camera from minus one to zero."
Please let us know how this solution worked out for ou. I tried it many decades ago and never found it worthwhile. For me it was preferable to ensure that the standard eyepiece was rubber-coated to prevent scratching spectacles.