Flycatch, I have a MDS 2.18 on a Dominator 1500 with a pitts syle bisson muffler. It had midrange issues until I blocked off one side of the muffler with JB Weld and starting using a idle bar style glow plug. I am still running it rich since it hasn't had but a couple of tanks of fuel through it. It pulls both 20X8 and 17X12 props with great authority. I am considering using this engine on a Wild Hare 28% extra. Can alway switch to gas later, if it doesn't work. You may want to try a similar statedgy on you 1.48. I have another thread on this project. Anyway, sometimes a Perry pump regulator when set up correctly can make a larger glow engine come to life. Have several friends using them on ST, OS and MDS engines and won't go back to a pressure tank. I have several ST 2300's and they make almost the power of the OS at half the cost. They are just more finicky to break in and get adjusted. The OS is almost idiot proof.

I am not sure how much the MDS 1.48 weighs, but the OS is fairly light weight for it's size and power output. I am running a bisson pitts muffler with one side blocked and with a APC 18X6W prop it has unlimited power. I am starting to consider setting throttle curves, since I only use about 75% power on uplines. I run either 5% glow master or 10% Byrons or Ultimate fuel in it. It isn't particular.

My CG is back a few 16ths further than yours. Mine came in a little hot, until I got the low end set right on the OS, now it comes in pretty good. This airframe is very clean, so I have had to use longer approaches to allow the engine to idle all the way down. I use a High Idle condition for flying and throttle down (Futaba 9C) so the engine slows down, almost to stopping. This gets it slow enough to land. I throw the idle-down switch once I settle on glide slope and announce full stop landing, then if it should go dead stick, I'll make the runway anyhow. Learned this from some Unlimited IMAC guys I fly with. Even at 12.25 pounds, this airplane is no glider, but have dead sticked it once and it came in great, even a little fast, but no problems.

Hope you get your engine running reliably