Hey, thanks for posting an interesting project.
I could not really tell what your question was though. Is heating element on the sides going to heat the wax faster? Probably not, but putting both a bottom element and a wrap around element might. For safety you need to carefully monitor the wax temperature where it is hottest. If you get to around 395 Fahrenheit, you will have an explosion. For efficiency you would want the heating element buried in the wax. For safety you want a closed loop proportional temperature control and at least two separate ways to measure the temperature and remove power before getting anywhere near the flash point, which for some waxes may be as low as 285, but in any case it is safest to stay below 212.