As far as cutting edge issues go, the issue of combining the basic nitrox certification with another class is VERY cutting edge. If someone suggests this to you, then please appreciate that you are speaking with an ultra-modern instructor.
NAUI specifically recommends combining the nitrox course with one of several other courses. Possibilities are to combine it with the basic open water course, or with the advanced open water course, or with the master diver course.
If you can get a special deal from a PADI or SSI instructor, where the nitrox course is combined as well, with a discount off the regular price of both classes, that would be a fantastic deal.
When I teach scuba, I like to combine the basic open water course with the basic nitrox course. The basic half dozen dives are limited to 40 ft to begin with, and that is a perfect depth for using EAN36. In other words, there is no ox tox risk.
The beginning dive students learn from the start of their training that there are 3 gasses available to them: Air, EAN32, and EAN36. They get to play with all 3 dive tables. They gain an appreciation for partial pressures and PO2 and FO2 and MOD.
I make sure they can personally calculate the MOD for EAN36, after I show them how to calculate it for EAN32 and for Air. It also helps them to understand why there is helium in technical diving, and why they should always limit their air diving to 100 ft.
Combining basic nitrox with advanced open water is also an excellent idea. This requires them to review their dive table procedure, and again to understand partial pressures and PO2 and FO2.
Either way, eventually your divers are going to go out and start diving in the range of 50 to 100 ft, and that is the range where EAN36 and EAN32 minimize the N2 DCS risks of diving. And that is the main pay-off for them. Safety.