From your comments, it is not clear if there is an ambiguity or inconsistency. You state that the WI stipulates a couple of options but it is not clear from your comments if the WI limits the form of construction to one of those stipulated or not.
If the WI is explicit in that only one of the forms stipulated can be used then there is no ambiguity or inconsistency even if other forms would comply with design standards.
If the WI is not explicit in terms of limiting the forms then, equally, there is no ambiguity or inconsistency provided that the proposed form complies with design standards.
You therefore need to review the WI to ascertain what has been stipulated. Does it expressly limit the choice or not.
If the WI does not expressly limit the form, an instruction to prohibit that proposed (assuming it does comply with standards) would be a change to the WI and therefore a CE.
If the WI is explicit in limiting the forms then an instruction to comply with the WI would not be a CE.
If the WI is explicit in that only one of the forms stipulated can be used then there is no ambiguity or inconsistency even if other forms would comply with design standards.
If the WI is not explicit in terms of limiting the forms then, equally, there is no ambiguity or inconsistency provided that the proposed form complies with design standards.
You therefore need to review the WI to ascertain what has been stipulated. Does it expressly limit the choice or not.
If the WI does not expressly limit the form, an instruction to prohibit that proposed (assuming it does comply with standards) would be a change to the WI and therefore a CE.
If the WI is explicit in limiting the forms then an instruction to comply with the WI would not be a CE.