I have yet to see an enclosure configured in a manner where it would be possible for the helmsman to see the jib's telltales, at a glance... Yeah, I know, most of them feature some tiny 12 inch square window to observe the main, plus the moon and stars... But, the only way to see the jib telltales is to leave the helm, unzip one of the deck "passageways", and crawl halfway out to have a look... Of course, this is only of concern to that pitifully small percentage of cruisers actually interested in SAILING, but still... (grin)

My view on these contraptions is akin to that of carrying weapons aboard... Rather than arming yourselves to the hilt against pirates, seems a lot simpler to just go cruising where they ain't... Rather than enclosing yourself in an oxygen tent/sensory deprivation chamber, invest in some good foul weather gear, instead...

Or, better yet, a trawler... (grin)