Yes, as said "In fact, go 1.16 has reverted to using this as the default now. The memory graph after this change looks much better and steady at 2G.". Upgrading is definitely next, not easy though since Google appengine flex still does not supported 1.16 out of the box https://cloud.google.com/appengine/docs/flexible/go/runtime
Right now we don't see any obvious scalability bottlenecks. The one problem we see right now is the user has to enter info about him (which we call iotas). Going further, we would like to automate this process as much as possible.
Ah, when I asked about scalability for commercial usage, I meant - how do you plan to make enough money out of this to scale it. An automated bot that answers questions about me is a novelty, I'm curious about whether you would make enough money out of it to sustain it:: which would then make it worth my time to enter data about myself.
We do not plan to make money out of it right now. If we reach a scale where we cannot sustain it off our pockets, it would be easy to raise money for it.