I don't recommend Dense Ores mining ages on a server unless you WANT the "economy" to be flooded in diamonds, iridium, and lapis. It kind of kills trading and progression.
Doesn't really matter. You'll still get plenty of those without. I have not used dense ores, mine by myself, and I still have blocks of diamonds laying around. A couple dozen blocks of lapis, and about 6 stacks of iridium. NTM another 30 stacks of UU matter....and I turned off my mass fab almost 2 weeks ago.
If you actually care about having an economy based off of resources rather than crafted items, you would need to make a number of changes. Disable quarry, disable miners, disable turtles, disable steves carts, disable mystcraft entirely. Disable matter generator/mass fab. ( The gregtech one just slows things down for a bit. You'll still flood the market with it eventually. )