I haven't done any advanced tech yet, but I have converted the WLF-1
Wolfhound:
WLF-1 Wolfhound
Weight: Light
Tonnage: 35 t, 1 Hardware Point
Movement: 3
Heat Dissipation: 2
Tags: Easy to Maintain - Laser Boat - Good Reputation - Lyran Commonwealth - Full-Head Ejection System
Armor:
Head: 3
Torso: 5
R/L Arm: 4
R/L Leg: 5
Structure:
Head: 1
Torso: 4
R/L Arm: 2
R/L Leg: 3
Weapons:
Group Damage Type Heat Location Pointblank Short Medium Long
Punch/Kick 1/2 --- --- --- OK --- --- ---
Primary: Large Laser 3 E HH RA OK OK -2 -4
3 Medium Lasers 5 E HH T OK OK -2 ---
Medium Laser (Rear) 2 E H T(R) OK OK -2 ---
Everything was pretty straightforward, save for Punch/Kick damage--the formula mentioned rounding up, but the examples round to the nearest whole number instead; I followed the lead of the preexisting 'Mech stats.
As for XL Engines, I don't see how they'd change anything in the conversion process--they don't appear to affect the Clan 'Mechs in the back of the book, at least. . . .