That's easy to do.
However, I'm not sure we should invest in that.
Moving forward with the multi-light shader, we'd need all light textures be the same size.
Even better, not use light textures at all - replace them with math formula.
That should cover 90+% of all lights in missions.
In other words, I believe the mappers should plan their design with the assumption that their textures will be compressed.
That means, as little "highQuality" material keyword as possible.
I believe it has been abused to an extent where at some point we might need to start ignoring it.
When it comes to lights, mappers should either accept the compression glitches or make an effort of coming up with a formula replacement. No more reliance on sheer GPU horsepower. There are people with weaker GPU's than yours - and less RAM. Give them a chance to play your mission.