I'd recommend that you use Img to burn the .ISO file and yes you will have to choose the layer break.
Not to worry, Img will prompt you and populate LB locations. They are color-coded in terms of excellent to average, but all should work ok. You can preview the LB location if you like.
Here's a link:
The exception to this is if the.ISO file already contains an .MDS file (LB location). This would be the case if you created the file with Img in read/build mode.
Your LH-20A1S will do a great job with the MKM 001 verbs, ie., 2.4-4X.
This burner, with firmware 9L08, is one of my work horses and does a great job with this media...best at 4X.
The Benq should work ok too...I have a 1655, but I find that the older firmware does a better job and I only burn DLs at 2.4X on the rare occasion that I use the Benq.
Hey Kerry...didn't see you there...
Typing at my usual "turtle" speed.
I believe you suffer from the "old fart" syndrome as well...