I'm a bit late to the party. I got some of this in the mail yesterday and roasted it today. Big thanks to JohnnyLSU for sharing a few pounds of his supply.
I started roasting on an Ikawa Home a few weeks ago, and I've only done around 15-20 roasts on it. That said, it seems possible to extrapolate my old approaches from my Quest M3 if I treat MET and inlet temperature as roughly analogous. (After all, inlet temp should be approximately the maximum temperature that a coffee seed would see.)
My general approach to roasting coffee is:
1) Start with plenty of momentum. Charge as hot or nearly as hot as possible without tipping. (This starts development early and helps ensure evenness of roast and good development of the inner bean.)
2) Roast quickly to preserve acidity. (But not so fast as to prevent development or aromatics.)
3) Spend at least ~18% of the roast in development to maximize solubility and development at lighter roast levels.
For high quality dry-processed Ethiopian coffees, I approach them pretty much as I would a washed coffee, and that was the case here. I don't find they burn terribly easily. I'm still adjusting to the Ikawa, and not having a BT measurement is definitely strange. But it's not as bad as you might suspect.
Roast
(1) was designed to spend a little bit longer in the drying phase and speed through ramp to maximize acidity and keep any bready flavors minimal. (The downside of a quick ramp with an Ethiopian coffee, in my experience, is potentially reduced florality.)
Charged at 0:30s, total roast time 5:50
Development ~25-26% (* hard to say since 1C onset is debatable with such a tiny batch)
11.8% WL

Roast
(2) was meant to impart even more early heat and reach development a bit faster, to maximize sweetness.
Charged at 0:30s, total roast time 5:50
Development ~1:30, ~25%
13.4% WL

Tasted
as a 12:210 v60-01, immediately after roasting (rested 10 minutes after grinding)
(1) sweet and juicy. strawberry, rapsberry, lemon curd, earl grey. good acidity. tastes somewhere between a high-quality washed Ethiopian coffee and a more stereotypical DP Ethiopia, which is good and typical of high quality naturals
(2) Sweetness is slightly more prominent and is extremely lingering. flavor clarity a bit lower. Was slightly bitter when hot but just sweet on cooling. Curious to try this as espresso.
I didn't get any onion flavors in either
Tasted at +2 days and preferred (1) strongly. It just improved in the two days. Solubility was also pretty insane, in both cases around 25% EY at a grind setting that normally produces 22-23%. (2) tasted woody and spicy in a meh way.
As espresso, (1) pulled very quickly and (2) pulled well and extracted well but tasted bitter and gross with my normal blooming profile. (pre infuse to 3 bars, then bloom for 15s before pulling at 2ml/s.)
I will try another variation or two on (1) and try an espresso roast, which will be basically the same but a minute longer and perhaps a faster dry / longer maillard.
P.S.: if someone feels like selling 2-3 pounds of the Royal Tej process, please message me.