I wouldn't worry about it too much. I did one Goenka retreat 10 years ago, which was very useful, since it was the longest, strictest, retreat that I had done at that time.
I came from a Mahasi background, so I hadn't used the touch of the breath much in any case. I'm not sure what you think is contradictory to the suttas (e.g. the first tetrad of MN 118) to just observe the sensations at the nostrils (but then I'm skeptical about most claims about consistency/inconsistency of techniques with the suttas - I don't see the suttas as teaching much detail about technique). Of course, that's not an ultimately complete practice, but the idea is to build enough concentration so that when you start doing the body-scanning exercises (after about three days) you are ready.
I've attended a number of other short retreats/daylongs with teachers who teach techniques different from than what I'm used to (including various Ajahn Chah students such as Ajahns Brahm and Tiradhammo), and I find they go much better when I don't internally argue with the instructions.
I presume they still use the same tapes of Goenaka for the instructions and Dhamma talks. As I recall, most of what he said was fairly standard Theravada, though with his own spin (as is the case for any teacher). I found just doing sitting was tough, since I usually do equal sitting and walking, so spent most of the short breaks walking to prevent my body from seizing up.
Another frustraion was that it was only towards the end that Goenka gave any instructions as to what to do outside of formal sits (as I recall the instruction was to just pay attention to sensations).
However, overall it was a great experience, and the "assistant teacher" was very helpful when I had occasional difficulties.
Have a great retreat!