Hi,
Thanks for your feedback,
It is only in the recent update on 18.02.06, that SAP have update the note and allow EHP4 to be upgraded to EHP8 with SP01.This is a yesterday news to us only. The date I am writing this feedback is 19.02.06.
Previously it was new and it was not possible.
At below of the of note there is change mentioned to the SP Stack 01.
(18.02.06) - Remove of restriction: Upgrade: We currently provide a direct ('one step') upgrade path from EHP7 to EHP8 for SAP ERP 6,0 to EHP8 for SAP ERP 6.0.