Hello, 

I bought the course yesterday and had a look at the line:   

1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Nxd4 Nf6 5.Nxc6 bxc6 6.e5 Qe7 
7.Qe2 Nxd5 8.h4 (Sethuraman's only suggestion) and now 8...a5 

which looks logical to me - very concrete  stuff. 

A sample: Line #2 (of 7 lines about 8...a5) continues: 
9.c4 Nb6 
10. h5!  (Sethuraman: "a rare move ...") Qe6 
11. Be3! Qxe5 (11...Be7 is another line) 
12. Nd2 Be7 
13. 0-0-0 Bf6
14. Nf3 Qe7 
15. Qc2 d6 
16. Re1 Be6 
17. Nd4 
"and White has a lot of play for the pawn." 

I used the analysis-board of chessable quite some time 
to get an impression of the position after 17. Nd4. 
I think White has to be careful, too and should better study 
this position before playing it in a serious game.   
I think before 17.Nd4 White can bail out for a draw with 16.c5.   

As usual you have the option to learn a line or to browse a line. 
Browsing lines is important because you will find some important 
informations only if you browse the lines. 
Sometimes Sethuraman gives very concrete reasons why he does not 
recommend a line or why he thinks official theory is not so good.   
Of course browsing all lines means a lot of work 
if you do it for the whole course. 

Btw: 
If you are serious about 8.h4 in the Mieses maybe 

Ris: The Scotch game (database, modern-chess.com) and 
Khalifman/Soloviov: The Scotch Game (book, chess stars) 

are also interesting and a good supplement. 
   
I think you have to work very hard to make Sethuraman's 8.h4 
work in your own games. 
Very good technique in the endgame seems essential sometimes.   

(After 1.e4 g6 Sethuraman aims for the Nf3-c3-build-up 
to spoil Black's fun, 
so at least not the whole repertoire is as complicated as the Mieses.) 

I am no theory buff and too weak for 8.h4, 
but maybe I will try it on Lichess anyway.