I wonder if it might be better to put the TW rules into more distinct tiers and focusing on Ground Operations (indeed I'd like it to be titled Battletech: Ground Operations Guide B:GOG), which each have their own chapters.
You have level 1 'basic/fast play' rules without tracking heat, ammo, or crits. Basically the pamphlet of how to read the record sheet and map (forests are cover, rough costs more, elevation changes what you can see) that helps you learn movement, hit locations, GATOR, the cluster table (including Artemis/Apollo), and some basic tactics. I'd even say no piloting checks, physicals, or indirect fire. This basically already exists as the box set rules because its really handy.
That can be covered reasonably quick along with easy to visualize diagrams, including a visual representation showing the front/side battlemech hit locations and numbers, plus a flowchart of turn order and unit activation.
Then you have level 2 'tournament/standard/limited' which introduces heat and critical rolls as well as more advanced (LB, Pulse, Gauss) weapons, physicals (all of them and modified slightly), indirect fires, piloting checks (from 20+ and critical damage), specialty ammo (all of them, so minefields included), equipment (like ECM, Stealth, TacComps, or C3/Nova) and some environmental effects (smoke, fire, terrain/building destruction) but not everything.
This would be benchmark, most of the advanced rules are really just a +/- 1-4 so having them all just listed out in one set of charts by modifier (for all weapon types) would be helpful.
Then you have level 3 'unlimited/extended' which makes all optional TacOps rules valid based on a scenario checklist. So it would have a section for advanced (and very niche) infantry, vehicle, and mech operations, plus abstract battlefield support, (air and artillery strikes, minefields, etc...), and the scenarios in which they would be most appropriate.
Closing Ground Operations you'd have Scenario Design which would not only have BV calculation (including the pilot chart, C3 mod, TAG/SG, etc...) but you'd have basic building (CF) and map sheet modifiers (wind, weather) as well as advanced environmental effects (water/vacuum breach, swarms of bugs, exploding objects, etc...) It would have a very standard template for the GM to neatly balance forces and conditions based on the intended mission.
Quirks and Special Pilot Abilities would be saved for a later Alpha Strike Commander's book. They kinda clutter everything up and need more playtesting IMO.