Five seems right to me as well, but is there a downside to keeping the preference and just having it default to five?
maximizerMRUList (user, now '-mana cost,-tie;slime hates it;-combat;adv;-mana cost, -tie', default 'mainstat;mus;mys;mox;familiar weight;HP;MP;ML;DA;DR;+combat -tie;-combat -tie;initiative;exp;meat drop;item drop;2.0 meat, 1.0 item;item, sea;weapon dmg;ranged dmg;elemental dmg;spell dmg;adv;hot res;cold res;spooky res;stench res;sleaze res;all res;mp regen;ML, 0.001 slime res;4 clownosity;7 raveosity;+four songs')
maximizerMRUSize (user, now '5', default '5')
maximizerMRULength=40
maximizerMRUList=item, food drop;0 beeosity, mainstat 999999999 max, +10spell damage +mysticality experience +5 mp regen min +5 mp regen max, item;0 beeosity, mainstat 99 max, +10spell damage +mysticality experience +5 mp regen min +5 mp regen max,;adv;0 beeosity, mainstat 89 max, +10spell damage +mysticality experience +5 mp regen min +5 mp regen max,
maximizerMRUSize=5
maximizerMRULength=0
maximizerMRUList=adv, switch disembodied hand;item, equip shoulder holder, equip dormouse;item;-tie, Four Songs, Additional Song;mox
maximizerMRUSize=5
maximizerMRUList (user, now '', default mainstat;mus;mys;mox;familiar weight;HP;MP;ML;DA;DR;+combat -tie;-combat -tie;initiative;exp;meat drop;item drop;2.0 meat, 1.0 item;item, sea;weapon dmg;ranged dmg;elemental dmg;spell dmg;adv;hot res;cold res;spooky res;stench res;sleaze res;all res;mp regen;ML, 0.001 slime res;4 clownosity;7 raveosity;+four songs)
maximizerMRUSize (user, now '', default 5)
maximizerMRUList=mox,-melee;mys,type chefstaff,spell damage percent;mus,melee,shield;mus,melee,1 hand;weapon damage percent
maximizerMRUSize=5
java -version
java version "1.7.0_17"
Java(TM) SE Runtime Environment (build 1.7.0_17-b02)
Java HotSpot(TM) 64-Bit Server VM (build 23.7-b01, mixed mode)