I will throw this out there as a suggestion as I am not sure if it will work.
When some change their timing guides on the M62 they cut the upper oil pan gasket where it mates with the lower timing cover - on reinstall they apply RTV or equivalent at the cut joints on both sides. On my RR, engine number 2, the shop that did the work used this approach. Based on the paperwork it held without leaking for 50k plus miles. On other BMW engines, mainly the M54, owners cut their oil pan gasket into two parts and seal the cut with RTV or equivalent to avoid the incredible labor involved in a proper replacement. These are metal caskets. This is done because the oil sump pump is in the way.
Using this idea could one do the same with the M62 - Cut the gasket into two parts - stagger the cuts somewhere in the middle of both sides and RTV or equivalent the cut seams/joints?
For the M54, the shortcut process is basically drop the pan by removing only the pan bolts, cleaning up really well, then position the two oil pan gasket pieces properly add RTV and bolt up. For the M62 (maybe use a number of longer bolts (at least 3 per side) to maintain alignment) RTV or equivalent the seams and the 2 or 4 specified spots and then tighten it all up.
If you do your homework you can find upper oil pan gaskets for about $22 by cross referencing with all the M62 blocks and electing the cheapest one. I found a Victor Reinz that fit perfectly and looked like the OEM one I removed off engine #4.
As I recall RAVE says to put RTV at the area near the RMS holder on both sides and at the two lower timing cover joints (Basically where the block has joints). Then just add RTV at the cut joints and tighten up.
The only challenge would be the oil drip coming down the sides, but if you let it drain for a few days, spay above as best you can, clean up and work fast this could be minimized. The challenge is keeping the RTV spots free of oil which would compromise the seal.
Just a thought - maybe others will chime in as to feasiblity with a fresher recollection of the upper oil pan gasket. I do recall some inner bolts and don't recall how restricted access is.
