Canadian (bubble) canopy Chipmunks should be flown with canopy open for take off and landing. That way if you end up inverted on the ground you can crawl out.
By the same token if you fly a 'glasshouse' canopied version you should take off and land with the canopy closed. That way you'll still be able to get out via the jettisionable side panels. Just slide your canopy to the first stop and then visualise trying to get out via the push-out panel - you'll see what I mean - you simply won't do it.
Otherwise I believe there is no limitation. At anything over 65 knots I struggle to slide the canopy. But it's worth it
