If you try to open the canopy to the taxi position In flight, you?ll most likely loose the canopy. That may be what you want if you?re still on fire and thinking of bailing. It may be difficult to open the canopy anyway in flight, but if you get it started to open, it will most likely be gone very quickly.
Try this: while taxiing, open the canopy a little with a FIRM GRIP on the canopy lock handle, and then push the throttle up a little (difficult to do unless you have two left hands). When I did that, it tried to pull the canopy right out of my hand. I had to quickly reach across with my right hand and close the throttle.
Make sure you have the canopy latched in the taxi pinned position during normal taxi ops before you add anything more than idle RPM, or you might get a surprise.
As far as smoke clearance goes, here is my observation..... when I first put a smoking airplanes system on my FB RV8, And I was trying to figure out the best flow setting to give me good smoke without going through 4 gallons in two minutes. Well, on one pass with ?smoke on?, I guess I had it dialed up a little too high because the cockpit went IFR - on the inside. I turned the smoke pump off and it cleared up quickly with just normal vents open. I eventually discovered if I had the back seat vent closed, and dialed the flow rate down a little, that didn?t happen, but to answer your question, opening the vents for smoke clearance should work well, as long as you have put the fire out.
RV6/2001 built/sold 2005
RV8 Fastback/2008 built/sold 2015
RV4/bought 2019 Flying