At cone 10, your clay will become vitrified -- making it very difficult to apply glaze to and then fire again at cone 6. Not impossible, but difficult and not always successful.
Check out John Britt's book The Complete Guide to High Fire Glazes -- it has a number of recipes for cone 10 glazes that provide bright colors; perhaps you can talk your studio into mixing a couple. Or, you could look for commercially prepared cone 10 glazes. Or, for your first firing, try some underglazes on test tiles to see how the color performs and then use those that are successful with a clear glaze in subsequent firings. You can get colors at cone 10 -- reduction or oxidation.
According to Highwater, Helios is 1% absorbent at cone 7 (less than 1% at cone 10). That would indicate it is rather vitreous at the low end of its firing range. I've only used it at cone 10, and can't speak to the lower end from personal experience.
I just fire to ^6 because I use stoneware clay and ^6 glaze. I think I should lower the temp and see what the result it. The thing is; I'm told that stoneware clay matures at 1230˚c to 1300˚ and if I fire under that threshold, then the clay won't be properly vitrified - if that makes any sense!
Firing to maturity (or vitrified) temperature makes absolute sense for functional ware; you don't want your vase seeping water. Knitting bowls are not functional ware in the sense they need to be fired to maturity to hold water or liquids. Glaze firing to a lower temperature will reduce the likelihood of warping. The only downside is the lower fired clay will not have the hardness of clay fired to vitrification. But, for knitting bowls, your stoneware glazed at low fire temps might be the solution.
"I have no doubt that the 3-D print fad will effect ceramics."
Near term, 3-d printers will be used for producing novelty items; watch for them to be the trend in MFA programs where the emphasis is on "art" ceramics. Right now, they are too slow for any resemblance of production volume.
Technology wise for pottery, the next big thing is more likely computer-controlled gas kilns. Just as manual electric kilns evolved into the modern digital, computer controlled electric kilns of today, that same technology will be used in the gas/propane world. And, prices for the technology will drop, making atmosphere firings more accessible to all levels of potters.
With pet urns, just contact local veterinary hospitals and work with them. Same for human urns, contact local funeral parlors and ask to have yours added to their selection. Probably more than enough demand locally.
Then, do work for your shows. Use the urns as a base product with steady income and the shows for other things.