David,
I'm sorry, but I'm not sure that I follow how this is pertinent to this particular thread. Are you proposing a way to replicate the scenario we experienced of our massively bloated TOAST table? If so, I'm not entirely sure that's doable given that the source of the issue was never clear. There still remains a number of reasons for why that table had so much "still in use" bloat. At this moment, it's near impossible to tell given that it is no longer a problem.
Thanks for the offer, and I apologize if I'm just slightly ignorant about your intentions.