Stop guessing. Clean the engine as thoroughly as possible and let it dry completely. Wipe down as much of the side where you think it may be leaking as possible. Now run the car for a few minutes. Now start dabbing at the engine to blot up any fresh oil which may have leaked out. Only go a couple inches at a time and keep checking the towel for wet oil. A leak can spray oil upward, but it's not common with oil and you'll know what parts you may check off your list of suspects. Make sure the engine has cooled enough not to burn yourself before you start reaching and shoving your arm against it.
DIY HG, first car, MKIII, oil leak, no mention of block prep..... I'm worried. Did you check the block deck for straightness with a machinist's straightedge? There was no significant pitting in the deck or it was properly addressed? You chased the threads for the headbolts? The headbolts were removed in the correct order and then when the head was reinstalled they torqued in the correct order and in multiple passes? What kind of head gasket did you use? Did you put FIPG at the lower rear timing plate and cylinder block union? Did you put FIPG at the #1 cam caps before putting the valve covers back on? Did you properly torque the valvecovers? Was the oil pressure sender removed for any reason? Were new gaskets installed on the turbo?
The drain is the 1" corrugated pipe which comes straight down from the turbo and then turns and mates with the block. The missing stay/support isn't going to account for any significant short term damage except for the possibility of inaccurate torque at the exhaust manifold. I would get it back on though.
Another location where it could be leaking is from the CPS. After you clean the engine check that area periodically too.