In my experience cyclical HRT is not a good way to treat PMDD or any condition that is aggravated by the fluctuations of a menstrual cycle.
If you wanted to artificially induce PMDD in a non menstruating population, think about how this could be done - yes, cyclical HRT!
Have you looked into options that include shutting down your own hormones and adding back a consistent daily dose to keep you on an even keel?
I use Zoely, which I take continuously, but there are other options if you can't or don't want to take a combined pill.
Regarding erratic bleeding on cyclical HRT - this is common and doesn't mean the progesterone isn't effectively protecting your endometrium.
Just because it isn't dangerous though this doesn't mean you have to put up with it, and if it continues I would look into other options, some of which are completely bleed free.