DevonDiver
N/A
This is possible...as there are no issues with swapping from nitrox to air at any time.
However, swapping during a dive is really is firmly in the realm of technical diving....as there is nothing covered within a recreational nitrox course that prepares the diver to plan or conduct dives using multiple gas mixtures.
Gas switching, particularly when you may be conducting dives where breathing the wrong mixture could mean exceeding PPo2/MoD... is an important skill that must be properly taught and mastered. Mistakes with gas switches, leading to O2 toxicity, is the biggest killer of qualified technical divers. Untrained/qualified divers should not be doing this.
The DSAT Tech 1 (or other advanced nitrox + deco procedures) courses would teach you how to maximise bottom times and depths by using more than 1 gas on a single dive.
