Yes that is well remembered Mary, gastric migraines! I was shocked with the diagnosis (endocrinologist) as I had always assumed migraines were about pain and I never had that. She also thought I may have had them since puberty but that my combined pill kept them at bay, as had neurological symptoms in my pill free week from about age 35, including a strange feeling of disassociation.
The migraines later were extreme nausea, like sea sickness (which was misdiagnosed as vertigo), twitching all over my body, a subtle weakness down my left leg and arm that would last for days, a pressure feeling in my head that later felt bruised on the back, right of my head, tachycardia to about 125bpm at rest and lots of eye floaters making my vision more blurred. I also had eye movement and sound sensitivity where at best watching TV or being somewhere where lots of background movement made me feel sick, and at worst I had to ensure my eyes were aligned with a spot on the wall for the whole day to not bring on the nausea. Some lasted 3 days, some 10 days and sometimes I just had constant low grade symptoms. All of this was amplified by GPs and A&E docs convinced my symptoms were due to a dangerous stomach ulcer, even though I had to wait 6m for a scan (hence, why I have now purchased private health insurance!) and was being, literally, force fed proton pump inhibitors at very high dose along with vertigo meds that make migraines worse! Perimenopause was never considered as I was only 46

So my clinic (London Hormone) have always wanted me to deal with one hormone at a time, although that may just be for my imbalances. Unlike other clinics I've read about here, they don't just do one size fits all. Once you know what works, there is the option to have a combined cream, although using patches or oestrogel/Lenzetto is initially offered as it works out cheaper.
I think when oestrogen is surging high you can either overwhelm it with high dose oestrogen (similar to the combined pill) to ramp down our own volatile production or subdue it with high dose progesterone. The latter is preferred as it means you don't need to then monitor the womb lining.
This time around, I asked for a separate testosterone cream last autumn to try once my progesterone had calmed the volatility. The dose was 0.5ml to take 5 days of the week. It made me feel similar to the oestrogen so I didn't continue it. Although my clinic also prescribe DHEA, I had purchased one before online and that had made me feel migraine like, nothing extreme but I felt it was interfering with trying to settle with just the progesterone.
It may be the case, and I've certainly read it on this forum, that oestrogen levels need to be high before testosterone is no longer converted to oestrogen. Could be the same with DHEA.