Happy Holidays!
142 / 12mm
I was also undecided between a 52 and 54. I'm currently riding a Elves Falath Evo 2023 with 378mm reach and 540 stack, all spacers, orome handlebar with 70mm reach and 100mm stem length.I'm almost the same height als you are with the exact same inseam and went with a 54 and a 80mm handlebar. You can check your geo and compare it at bike-stats.[de], with handlebar numbers even. [https://xybikecalc.com/] is also an interesting site, where you can compare geo's in raw numbers and see how increasing or decreasing certain values change the stack and reach of the selected bike. My Falath evo also has a 25mm setback seatpost and the 54 compared to the 52 has also the higher stack without increasing the reach too much (only 4mm iirc). The bigger frame will be more stable on the rougher terrain I guess and there's more space for bikepacking bags, which I also want to do with this frame.I don't have the frame yet, so I can't give you feedback on the actual fit, but that's the theory I've gone with. Maybe that's helping a bit.