Shipping method logic problem

Could the shipping method rules be expanded? Atm I'm having several types of products in a webstore. But one particular product type is never large nor heavy when ordered in the quantities our regular customers order them in. We can ship those products for €4.95. This product type is a very frequently ordered type. But as soon as any product of another product type is added the dimensions exceed the €4.95 rate max dimensions and we need to charge at least €6.75.

Currently that is possible, but it looks strange.

• I restrict 4.95 to product type A only[/*:m:f1zjju1g]
• I do not restrict 6.75 to any product type because it can contain both A and B, C, ...[/*:m:f1zjju1g]

I end up with both prices showing for the exact same option when customers only order type A!

A possible solution I thought of would be dimension based shipping, however, in this specific case the dimensions are unknown because ALL products have configurable dimensions that the customer chooses, but some products can be send disassembled (Ikea like) where other products cannot. So the program code that should handle that will be more complex then using just the dimensions field!!

Is there anything that can handle this already, or is there anything planned?

(This store sells prints, canvas, metal frames, banners and such. All of these are custom made. That is why dimensions (and even weight) is a complex matter)