[cflsystems]

I've been asked in relation to this mod how to keep the coupon messages popup but disable the message when customer creates/updates account info

Not tested but in /skin/common_files/modules/One_Page_Checkout/ajax.checkout.js find

 
ajax.widgets.checkout.obj.prototype._callbackUpdateProfile = function(data) {

and comment out this line

 
this.showMessage(data.content, 'I');