Forgive me, but your request is a little jumbled.
On one hand it seems you're asking for housing crates to be able to hold containers (boxes and bags), and on the other hand it seems you're asking for large crates to have slightly more capacity. Not sure if you're asking for one or both...heh.
If the former, then I'll say it won't happen, due to technical/database issues.
It's a little inaccurate to compare bags/boxes with crates as crates can hold 30 items regardless of size, whereas bags and boxes can hold up to 35 items but only if they take up one space. Any larger items will reduce the amount that can be held by a bag or box, whereas they don't affect the capacity of crates.