either COA has its risks versus benefits
having now been given something else to consider I still don't think it's an option
having some experience with ne'er-do-wells I would put the odds at 95% that your location becomes compromised prior to ever needing it...the type of location you describe are routinely utilized by homeless, gangs, crack ho's and others
I think that in my area the likelihood of location compromise is more at 100%
just my $.02
The family estate owned a building like what you talk about, and we spent a lot of time, effort, and money protecting it after ferals noticed it was empty.
We finally sold the building this year, thank goodness.
/johnny