In using nothing but 18650 IMRs, my primary concern with the Telescope is the lack of protection against shorting (which is the primary cause of IMR failure). Thus, I see the Holocron Labs ShortStop to be the singlemost important safety measure for me to take.
As for the venting capacity concern, this largely belongs to those who intend to stack li-ion batteries (or who fear that others will). However, the informed consensus appears to be that all battery mods should have gas vents, a master on/off switch, and some sort of protection circuit.
Since the battery spring in the Telescope mod is physically separated from the body and battery (with a plastic cap on the battery end and something that some are calling a bunch of glue on the body end), I consider the Telescope's firing pin to effectively be a master on/off switch. Especially since it can be easily locked into the ‘off' position whenever the situation warrants it. Thus, between this fact and my use of the aforementioned ShortStop, the only question remaining is whether or not there is sufficient venting capacity to handle an overheated, gas-expelling battery.
When the Telescope's venting capacity issue was first brought up, my first inclination was to compare the venting capacity of the Telescope to my VV Torpedo mod - which was the only thing I had to compare it to. I did not use balloons, but in using my mouth, lungs, and perception, I estimated that the Telecope's total venting capacity was approximately 30 to 50% of the Torpedo's. (My Torpedo had been gutted out for other reasons which made it easy for me to do this.) Nonetheless, after having thought about the matter for awhile (and done much reading about battery and mod safety), I think that I would feel a little safer with a greater venting capacity.
It's unclear what SmokTech intends to change about the lower battery tube to increase the Telescope's venting capacity, but I think that I am going to drill eight 2.0mm holes through the bottom cap and threaded firing-pin lock like this:
View attachment 125171
The image above is a bottom view of the Telescope minus the firing pin. So with the firing pin in place, the holes will not be very visible. More importantly, in the unlikely event that the ShortStop should fail to work when it is needed - leading to a temperature rise that results in a venting battery, there will be a counter-pressure created by the streams of gas pressing against the underside of the firing pin cap. This should prevent any bottle-rocket-headed-towards-my-face type of outcome that bottom-end vent holes can lead to.