Here is a pic of a ported head done by someone who thinks a lot of his work.....
The problems here are multiple, I have issues with his view of how to port to increase flow, but leaving that aside, the real difficulties are that he thins the bifurcation too much, this causes reflections in the port - flow is always better around a generous radius rather than a knife edge, - but more importantly it becomes so weak as not to be able to withstand the insertion of new valve seats once thinned to this degree, this may not matter in the short term, but if a MS2 head needs new seats at some stage [and you cannot go on recutting them forever] the bifurcation will crack even if the head is heated and the seats are frozen in a nitrogen bath.
Worse still, the seats are hand cut giving horrible results, and the individual involved described to me how he lapped the valves in with a drill and lapping paste - this results in all th heads from this source having worn valves and sometimes bent from new. One individual I built an engine for some time ago had a whole head built up from this source, - the valves and seats were so bad he just flogged the whole thing on unused for less money than he'd paid to have the work done.
A modern properly jigged valve seat cutter must be used under all circumstances - never ever be fobbed of by less -
