Creating new columns from data stored in JSON format

Hi.

I'm getting data from a REST feed in to Power BI.

One of the columns contains information stored in JSON Object format.

e.g.

{"String A":"Value A","String B":"Value B","String C":"Value C"}
{"String B":"Value B","String C":"Value C"}
{"String D":"Value D"}
{"sTRING A":"vALUE A","string B":"value B","String C":"Value C","String D":"Value D"}

If I use the inbuilt JSON parse feature it changes the column into a Record for each row. I can then expand the column and it will create columns for each of the strings with associated values stored in the appropriate rows.

This is the functionality that I am after but there are 2 problems I have discovered that I can't find a resolution for:

1. Where case for the strings is different ("String A" vs "sTRING A") the column expansion views these as different and creates two separate columns. I require it to be case insensitive as the data coming in can be in any case. Is there a way to do this?

2. The column before expansion can have a variable number of strings in it. As Power BI only imports 1000 rows for manipulation, it doesn't actually parse all the rows so it doesn't create columns for some required strings that aren't brought in in the first 100 records. Is there a way to fix this?

Thanks for any help.

John.