Battles in BrikWars can get really quite large and most BrikWarriors are of the distinct opinion that it would be a damn shame not to enjoy them and all of the wanton, chaotic possibilities they bring simply because there aren't enough briks to go around. MicroScale battles are the answer to that call to arms, scaling down large scale battles (and associated costs and real estate) to more manageable chunks and helping to remove the barrier to entry on many BrikWars experiences players wouldn't otherwise get to engage.
Microscale AGT Rulesets
Brikspace "Epic" Supplement: 
It should be noted that Brikspace is a sort of "jack of all trades, master of none" of MS rules. It works okay for LDD and real life battles, at small or epic-scale engagements, but it doesn't carry any optimizations or downsides in any case.
Theblackdog's Microspace Ruleset: 
Theblackdog's ruleset is optimized for small-scale tactical real-life microspace battles, emphasizing movement and strategy.
Epik Space is optimized for epic-scale fleet engagements involving hundreds or even thousands of ships, including dreadnoughts. It simplifies BrikSpace and eliminates a lot of details and dice rolls.
Quantumsurfer's alternate take on the base game is a microscaled version which uses a modular battlefield for the ease of use while running battles in LDD or to ease part usage IRL.
Quantumsurfer's take on microspace. It's an abstracted, zoomed out, starship scale system with an emphasis on ship play performance and is intended for skirmish level play.
A catalog of everyone's LXF files for use in LDD microspace battles.
It doesn't matter