You state that the outside of the ComputerCube changes when a graphical update occurs, I am guessing by that you mean when the chunk is re-rendered to its cache. Considering that I notice that the Centrifuge causes it to update in synch, which seems like the centrifuge animation is actually block updates (which are rather exceedingly costly), compared to a TextureFX (also costly, but one time per frame, not per block), or a TESR (much less costly than the others each, but can scale badly when you get above a few hundred per visual 16x16x16 chunk, make sure to use a display list). Is this the case, or does the ComputerCube update its texture during other situations beyond chunk cache updates? If that is the case then using a TextureFX or TESR would be far less costly and would not cause that renderable to invalidate.
EDIT: A few question as well
I know you are looking for a use for the Helium cell, but burning it is certainly not a right one as it does not make for a good fuel like that as Helium does not burn well by itself.
Modern things that Helium is use for it for evacuating the cavities of rocket engines since it is non-combustable; it is also used for superconductive purposes as it can be quite useful at keeping things very cold (a recipe part for your superconductive cables perhaps?); Helium is used as a very effective heat transfer medium since it is not effected by intense magnetic fields as other things are; Helium-Neon lasers have very common uses (standard laser pointer, not powerful, but easy); it is used as a high-speed push-gas medium for missles and such things; it makes a *VERY* good cooling medium for nuclear reactors due to its ability to absorb and disperse heat and since it is incapable of becoming irradiated (another use!); cryogenics; windtunnels; leak detection agent; and of course a lighter-than-air-lifting-agent.
A Sci-Fi story that I do not remember had a human faction using helium with extra electrons in an enclosure in their hand and tank weaponary, the enclosure was kept in a positive magnetic field and when the whole thing launched and hit a target the enclosure broke releasing a large zap of energy as it interacted with the positive field. It makes no real scientific sense, but there are plenty of such ideas as well.
Please no iridium drill, the current drill is *WAY* too OP for its cost as it is; like really, 5 iron and a circuit and a battery gets you an infinite tool, that is crazy OP, but then again so are many things in IC2 (hence why I hold out hope for this mod rebalancing it).
Quantum suit should also be far far higher tier, perhaps Tier 4 or 5 (Graviton or whatever it was suit being even higher). It takes a lot of iridium yes but that is really its sole prevention point, and by the time you get the tech to make one, you can just start pumping them out shortly thereafter. Those things should be an achievement, like requiring a fusion reaction to make necessary part, like for its internal power cell or so, that would be another good use of the fusion reactor.
As Kane_Hart hinted at, UUM is rather *WAY* unbalancing for server play (which I do), it needs to be reigned in, very badly, perhaps replace the mass fab with somethiing that require a specific set of raw ingrediants to create the UUM, perhaps that could be another use of Helium, as well as hydrogen, silicon, and a dozen other things. If you make it more expensive to make UUM then what the recipes can create, then it becomes balanced and will not be used for 'har har I can make anything for free now' kind of thing.
The Fusion reactor itself, I see so many possibilities with it! Quite a few reactions you can do to create new types of raw matter. I do not want to see it creating things like iron as it would just become a bigger mass fab then, but so many possibilities with it.
Everyone on my server also finds the macerators ore doubling (and especially the blaze rod->5powder) recipes disturbing. They have voted it off the second there is a way to make the required recipe parts from it (like coal dust and such). We actually like the Factorization mods method of ore yield increase, grind an ore to dirty gravel of that type, clean in mixer to make a clean gravel of that ore type, slag in a slag furnace to make a reduced gravel of that ore type (with possible leftovers), then crystalize in a crystalizer, then cook in furnace. Each of those steps take a very long time, few minutes for grinder, a minute for mixer, about 20 seconds for the slag furnace, and about 20 minutes for a crystalizer, each step has a percentage chance to double its output based on the step, but you can cook the results at any time to get the output, at reduced yield, but after all that work (and a lot of work it is, each machine has a bit of unique 'upkeep') the average final ore yield is about 300%, which although higher than the macerator, is also *vastly* higher on the tech tree while taking a good deal of time, so it is costly to expand it as well. Not taking that exact system, but rather the style of having a long ore processing process across multiple machines and so forth is something that my server goers do like, it makes them feel accomplished by reaching it, rather than getting a macerator inside of ten minutes (which they do, the people on my server work together).
Overall we are liking this mod on my server, it seems to be starting to bring balance to an otherwise unbalanced mod. We ran without IC2 for a while there due to how extremely unbalanced it is, but we are testing again. Within just a few days we have UUM pouring out of everything, so much energy and nothing to use it on but just 'more' mass fabs, and as such. Some more energy sinks would be nice too, something to use our energy on, whether railguns and multi-block big beam projectors or defensive systems or force fields (MFFS is becoming less based on energy and more based on forcicium irritatingly) or whatever, we need more end-game energy sinks, and a removal of UUM as it is, that needs a big overall from just becoming the magic resource generator that it always ends up currently being.