Li Shenron
Legend
If you are now venturing into the boulder maze, we should agree on a marching order, or more appropriately a "crawling order"
We can use the same order as initiative (we can keep that order also for the fight continuation), unless some of view specifically want to stay in the front or in the back. There are different routes, if you want to split the party (!).
With the dim light from Sulannus' spell, nobody will have visibility problems, but let me otherwise recap the weapons limitations you are expecting, should you need to fight while crawling between the boulders:
- ranged weapons won't work
- bludgeoning melee weapons won't work
- melee slashing/piercing weapons that are neither light nor finesse will have disadvantage*
- light and finesse melee slashing/piercing weapons have no problem
*except for Bartleby

With the dim light from Sulannus' spell, nobody will have visibility problems, but let me otherwise recap the weapons limitations you are expecting, should you need to fight while crawling between the boulders:
- ranged weapons won't work
- bludgeoning melee weapons won't work
- melee slashing/piercing weapons that are neither light nor finesse will have disadvantage*
- light and finesse melee slashing/piercing weapons have no problem
*except for Bartleby