It calculates only the item's weight basis, does not support package dimensions. may be suitable for small items but definitely not for the boxed or bulky items.
Thanks very for your feeback. We have included your concern into our app description and other customers can be aware of the limit.
The limit is due to shopify's limitation that no dimension can be specified for products therefore no shipping rates can be calculated by dimensions. However, if the eParcel account has a cubic factor factored in, a work around is to specify the adjusted weight for products.
We've used the App for a couple of months now and all working fine. Bit of a set up with AusPost back and forth setting up the system with their developer team but step by step u get there. Support is fast to help but sometimes communication is a problem so be very very clear with what you are asking. Overall 5 stars for the App, it does what it say it does with no hassle after set up & the developers are nice & helpful.