Range of board is already something to add on the list, simply because not everyone’s requirement is the same. Having a few “standard” designs that would work for everyone is a better way to go.
As for making the board longer, that is definitely possible, however that too, some folks want something as small as it can be, with all the bells and whistles. Think of hula hoops where someone might not want a large gap in the LED string (to accommodate the board and battery.)
From my experience, the smd strip should be able to fit along side the control board in a hoop, so should cause no gap to be created. I’ve only used a femtoduino or the small RGB rf strip controllers, but both have been fine. And then I’ve distributed the cells evenly throughout the hoop so it’s nice to use. You can fit 10440cells along side water proof 5050 smd inside 5/8" internal diameter poly pro.
I can see a need for the smallest possible board as well, but for props which need to be thin (hoop, levi stick, devil stick) , I don’t feel length is really a constraint, until your at lengths when the curvature of a hoop will become the issue. Which should allow for a move powerful board for those props.
The only prop I can think of where you’d want the smallest possible board is diablo. A POV diablo could be pretty cool.
Diabolo? Yeah but it’ll be small, size of a CD.
I can speak from personal exp. 5/8 is extremly small tubing. 10440 largest cell is around 500mah that’s not going to run anything very long with a nice pixel density.
And I can tell you that an 18650 Power Cell will not fit. You need a 7/8" ID for that. My POVpoi baton uses one of those. 192 LEDs bursting 11Amps on a single cell. Easy.
Can also tell you that adding more then 1 14500 quickly becomes a weight and wiring headach. Its also really easy to crack led drivers like lpd8806 inside of a hooo due to battries and the curve of the hoop.
I generally use 6 10440 in a 3s2p 11.1v setup in a hoop, for a 12v strip hoop. The one hoop I made with the addressable strip was using 12 1.2v aaa in 4s3p. Which is fine in 5/8 poly pro. I was using ws2811 strip, so didn’t have the driver to worry about
For my poi I’m using half of http://www.hobbyking.com/hobbyking/store/__17281__Turnigy_nano_tech_1400mah_2S_15_25C_Lipo_AIRSOFT_Pack.html in each poi, with strip on each side, 2sided rather than 4 with lighting gel to diffuse them.
size comparison between 18650 - 14500 - 10440 and tubing size.
… your using lipo in poi? … you sir are a brave man.
Those are fine, they won’t work for my design though, won’t fit. I have four sided POVpoi with a control board that has buttons, USB and DC charging, and the SD slot, all sealed inside the tube with necessary holes in the wall (two in the side and one at the end, in the rubber plug for the DC charge plug.) So it’s not necessarily water tight but one can easily just tape over them if it’s raining.
Single battery which will last several hours too.
Larry, remember I design my own control board and LED strips, so I can get them smaller/thinner than those ready made boards. 
Not to mention custom.
Yours are looking really nice, I’ve been following them, just haven’t really posted in the group. They’re similar in design to the first set I made but far nicer, I’ve gone for something smaller for current pair I’m working on as having poi which I can actually spin is more important to me than drawing accurate pictures.
@Larry1 can I ask why it’s brave of me to use Lipo? Electronics aren’t really my speciality and I’m worried I’ve missed something. I made the choice pretty much exclusively on it being the form factor I needed.
Ashley it would be impossible for me to forget about your custom circuit design.
This thread is gold. I need a real computer to comment on all of the things you all are saying. Great knowledge sharing going on here. Makes me smile!!!
That’s why I LOVE this group of people. I’ve learned so much in like last year or so here its unreal. Plus I’ve met some truly amazing people that I’m honored to call my friends.
Any battery can be dangerous, not just lithium ones. You can start a fire with a 9v one, easy.
Hit enter too soon. Anyone working with any kind of rechargeable batteries, accepts a certain level of risk. Yes, some are more prone to issues than others, but if you treat them well, there’s no reason you can’t have a very safe product.