回複：再次麻煩PIJANG 和各位： H１B轉F１時身份出現GAP。 非常感謝。

there is no gap as far as I can see.7/29 is last day, you send out app, got receipt on 8/7.

no problem even if you have gap.

I remember when you do h1b trasfer, you only need to fill in month/year, not date.
I saw people with a few month gap got h1b transfer approval and finally GC, I highly doubt even you have a few days gap will make any damage to your status.