Of course people thought about interpolating curves and some even shared examples how to do it. I suggest, study these two gifts from Sed4tives 

stf-2x2-curve-tool-small-grid

stf-faux-bezier-rotunds

Perhaps you could take inspiration from Poznań?

I used 2x2 filters, as I always do.

LOLOL, whats that curve type called? —Must be something along the lines of, "cloud-pillow" rotund, "speed-bump" curve or  plain simple "wobble" instead of "curve".
Could be usefull for someone who is planning on making a decorative style lettering with a clouds or floral theme to it,  or perhaps something "whip cream" related. 

#pies, tarts and pudding-font

lol, yeah you should check out the FS-tools I have shared in the past.. thats all you need to get u started!

Circular parts or "arc segments"  with a chordal distance of (1 × 2),  (2 × 2), (1 × 3), (2 × 3) or  (3 × 3)  grid units is somewhat childsplay.

I know that for many new and fresh Fontstructors this whole "curved" letter geometry seems to feel like this forbidden fruit, or the "holy grail" in fontstructing.
And although never Fontstruct's first intended aim, to be a tool that would even remotely resemble a tool that would be used for approximating real curves. At first glance this very limited "round" stock bricks provided in brick-palette it might even appears that indeed this isn't, especially to any new users. But to just say that there is a lot more that can be achieved would be somewhat of a understatement. And the grid might even surprise you.
But when the editor is then also combined with the filters settings and modified composite bricks, suddenly Fontstruct begins opening up its true personality.

—For some of my more  experimental endeavours in approximating near (true) Bézier smooth curved letter-geometry I think (7 × 5)  is about the furthest I so far was able to stretch this.

Most important rule of thumb is this: More bulk (or weight, body) a letter component or segments the more there is to pull-off tricks and crazy impossible modifications.

And what do you think your geographic location  has anything to do with the ability to become a "Patreon" ?? 

You could even subscribe and become a patreon from way up there in orbit aboard of the International Space Station (ISS). No problem. Now,  you said u live in the US (CA), so...

(ISS)  🤷🏽‍♂️  🤦🏽‍♂️ CA (US) do the Maths again son. 🤏🏼

Oh and in terms of making shapes, curved or, not curved, has zero to do with actually becoming a "Patreon", which only allowes the use of additional extra coloured layers in the FS-editor. Thats all..

No doubt...