There are 2 ghetto fixes as mentioned:

1. Use "EricTheCarGuy" trick as mentioned above. Longer bolt to grab more threads.
During tightening, just take it easy, gently tighten it and snug a bit, that is all you need to get a good seal.
I usually place the wrench at 5 o'clock position and go to 6:30 o'clock (45-degree turn) and done with.

2. Use a slightly larger bolt but stick to SAE bolt.
Just find one that is close enough in terms of thread pitch and size.

All you need is a 1/2-inch bolt has a diameter of 12.7mm. It may work. Give it a try.
Find an SAE bolt with thread pitch similar to factory.
Once done, use a slightly less torque when you tighten the bolt.

See the threads by delirium45:

DIY: Fix stripped drain bung for oil pan - BMW M3 Forum.com (E30 M3 | E36 M3 | E46 M3 | E92 M3 | F80/X)

There are aftermarket versions of the lower pan available in the $60-$100 range. Not sure a Timesert is better than that.

New Lower Engine Oil Pan for E53 00 03 BMW x5 4 4i 02 03 x5 4 6IS 11137500210 | eBay

From a cost and labor perspective that replacement pan is definitely a better deal. Wonder if the pan is of decent quality.