Installed the 42t today. I noticed a little more top end. I might try 44t in the future after a few commutes... I still have plenty of climbing gears left for trail riding.Oh, no! Now you have asked a difficult question! Probably not.
If you trust me (and have engaged the derailleur clutch after your work is done), you could safely remove the chain guide. The chain guide is meant to protect the chain during really wild rides including jumps. In more normal operation, with the Praxis Wave or a Narrow-Wide chainring teeth properly matched to the chain links, the chain won't drop. I have ridden for many thousand of kilometres without even the chainguard on my big Vado, and I stupidly was riding rough terrain many times!
@Stefan Mikes You're right about the chain guide not fitting. It almost fit, but not quite. I wonder if there is a taller black bracket that connects to the bike, allowing you to raise the chain guide up a little higher. You can see the bracket sticking up in this photo... it just needs to go up a tiny bit more for the guide to clear the 42t.