Is there any way to arrange the parameters/UI in an hda to get an array of data block/struct?
For example I would like to have an object merge coupled with 2 float parameters, then every time I add a new object to the list, a new set of float parameters are created corresponding to that new object.

Object 1
float param 1a
float param 1b
--
Object 2
float param 2a
float param 2b
--
..
--
Object X
float param Xa
float param Xb

if I understand correctly, you might want to look into multiparms folders.