I have seen a Facebook Group called “Hiking Magoebaskloof”. There does not seem to be a lot of activity but perhaps you can contact their admin?
I have also posted your request on the “Magoebaskloof” Facebook group which does seem to be active.
Lastly, have you tried the deets in Hiking Trails of South Africa? See below:
Permits: Komatiland Ecotourism, Private Bag X11201, Mbombela (Nelspruit) 1200, tel: (013) 754 2724, fax: (013) 754 2790, email: ecotour@ klf.co.za