What if in the next two-plus years, Tesla starts to promote a "workplace" charging program a la the destination charging program?
I don't consider this a
'what if' so much as a likelihood. Workplaces will offer such benefits, because it will be available to their own fleet vehicles as well, in time. Many airports and seaports use electric vehicles in support roles, from baggage carriers to forklifts, already. Some use short range pickup trucks and passenger carts that are fully electric as well.
There are already publicly available
'free' chargers on public or government property. Adding Destination Chargers at Libraries, Courthouses, Shopping Centers, Movie Theatres or other facilities where people might be parked for an hour or more should be fine. Being able to acquire the hardware at no cost would usually be enough to get a City Council or City Manager to accept them without issue.
In metropolitan areas (including cities with moderately large populations) would this help alleviate this putative Supercharger congestion?
It would be an added convenience. Supercharger
'congestion' is not something that I expect will be a problem due to population. A minimal quantity of individuals who use Superchargers incorrectly can make an issue seem much more pervasive than it really is. If three or four people use an 8-stall Supercharger as their personal parking spaces, leaving their cars in place for hours during the day, that greatly reduces the rate of throughput for everyone else that needs to use it during the day.
Would it be persuasive and convenient enough for those without home charging to utilize?
It could be. But only if the places they are located are sites they would be visiting anyway. Most public charging facilities accommodate only one or two vehicles at a time. That level of distribution would not help much in public places. Perhaps at a minimum of four charging stalls, it could help.
Or would we be just adding another "free" resource for small-time chiselers to exploit?
Don't worry about it. The idea is to offer an incentive that moves people off of fossil fuels for transportation. This gives the benefit of improved air quality and lessened dependence upon limited resources. It isn't enough to only use less fuel per vehicle. Eventually, we must stop using petroleum byproducts as fuel entirely. Better to make that transition before it runs out or becomes too expensive for the public at large to use affordably.