Don't worry if it is not something that has a wide appeal.
I don't think there are many people who would like to throw away their raw originals. I see in your case why you do though.
Personally I wouldn't bother converting these files at all though. All that hassle for only a couple of megabytes of savings. Heck, I keep my HDR files as 32-bit smart objects these days, those files are >700MB each so I wouldn't worry about a measly 10MB
. Oh, and to make matters worse, I also maintain a 16-bit flattened version of those files as PM can't view the 32-bit files... (this is overkill, I know). Adding up to almost a GB per image (not forgetting about the 5 to 9 raw input files either). Hmm, guess I must be glad I don't yet own e.g., a D800