Thanks to everyone for your input. Just wanted to give an update in case anyone was interested.
About a month after my initial post I had reduced watering to once a month in mid-high 90 degree weather. The flowers and leaves stopped dropping and I was already very happy with the outcome:
Two months after my initial post I maintained monthly watering in low 100 degree weather and I am amazed at how well it's grown. I love all the bright pink blooms:
So, I've found that the desert rose really does take neglect lol.