That's the only case where luxury seating makes sense. You're not gonna sell a lot of seats, so sell them costly. It's not as good in terms of income, but at least it's doable. Tech stop has a plain 40% demand penalty, and it's really a PITA. If demand is, let's say, 110-4-0, you want those 4. So make a seating with 4 business & 50 economical; to reap the maximum of benefits of that line where you can carry only 54 people.
The best thing to do, however, is to have the proper plane for the job. Extremely long range can be fun, and make some money, but it's clearly not a game-winner. The kind of things I did describe in the first paragraph is really dark moves, with a high risk, and a low reward. And needs tons of micromanagement. I'd go for Jeddah or Kuweit, in your case, and keep Ryadh for a plane with longer legs. Without tech stop. The only tech stop I have is between LCY & JFK, and that's just for roleplay purposes. Economically, it's a bad joke.