I've been working with a similar pattern over the past several months. My personal opinion is that it is ok to mix these two conventions depending on the needs of the plugin. If you have a small number (i.e. < 5) of well defined parameters or if you want to select elements based on a particular attribute then data selectors for each parameter is ok. If you have a large number of parameters, or if the parameters are highly dynamic (i.e. request parameters to an ajax call) then json within a data attribute may be more beneficial.

In any case, IMO it is very important to clearly document what the parameters are and how they should be used.

I've been working with a similar pattern over the past several months. My personal opinion is that it is ok to mix these two conventions depending on the needs of the plugin. If you have a small number (i.e. < 5) of well defined parameters or if you want to select elements based on a particular attribute then data attributes for each parameter is ok. If you have a large number of parameters, or if the parameters are highly dynamic (i.e. request parameters to an ajax call) then json within a data attribute may be more beneficial.

In any case, IMO it is very important to clearly document what the parameters are and how they should be used.