I elected to submit an Enhancement Suggestion from the pull down menu of  the reporting type of problem. I filled-in all the required fields, write all 1,,2,3, sections in the details but when pressed "Submit" I got a refusal with an advice to do it via "My ERs" section of the Customer Portal, which in turn is not available for submission of new SRs during Beta Testing

I don't think the above arrangement is reasonable. If SW does not accept Enhancement Suggestions at "Beta SR Creation" page then the type "Enhancement" of the reporting problem should be removed. Also, "My ERs" should be open for submission of new enhancement suggestion during Beta.