It's an interesting question, but there is extremely little scientific data on this topic. Most people who have measured hypotension actually have hypertension and are taking drugs to lower their blood pressure. All the research that I have found about reducing hypotension has to do with adjusting the drugs to treat hypertension. And for reducing hypotension that is not related to medications, nothing. No research, except for this article that says don't ever try to raise blood pressure: https://www.sciencedirect.com/science/article/abs/pii/S0002939410000346
Keep in mind that the only accurate way to know if you have low blood pressure, nocturnal hypotension, or extreme dipping is through ambulatory blood pressure monitoring (ABPM). If you have a self-tonometer to measure your eye pressures at home, and you suspect you have hypotension (or hypertension), you might find an ambulatory blood pressure monitor useful. These devices cost about $2000 for a clinical grade model (and may require a perscription). If you own your own, you can do an ABPM study whenever you change your medications or supplements to see what effect might happen. An ABPM study is incredibly informative and recommended for any hypertension suspect, as well as glaucoma patients who are on hypertension medications, but the devices are underused in the US because of the insurance payment limitations.
I used an ABPM to confirm that topical latanoprost did not affect my blood pressure. Next up is testing 2 supplements known to have the usually undesirable side effect of raising blood pressure, licorice and gingko. Testing one at a time, of course, to see if they can bring blood pressure up to an acceptable level. Without the ABPM, though, there is no way I would ever know if the supplements have any effect on nocturnal blood pressure and dipping. Hawthorn extract is another supplement that naturopaths recommend for blood pressure regulation. But there is no way to tell if any of these ideas will work for you, or even be safe for you, without ABPM.
I have low BP at baseline prior to taking any supplements and the blood pressure is mostly the same 2 years into taking a lot of supplements. Had a sleep study that verified episodes of SBP 78-85 during sleep. I found that citicoline whether 500 mg or 1000 mg, would reliably raise my blood pressure by 10 or 15 points or so during the day. I now only take 500 mg an hour or so before sleep to try and mitigate nocturnal blood pressure drops.
I gave up melatonin (was only low dose) as it finally became obvious that it was worsening an issue with sleep apnea despite being a very thin person. Have to wonder if the too deep sleep was also bottoming the BP. After stopping it, intense morning headaches stopped. Really regret having been on it so long. As far as supplements otherwise having the most impact, it seems to be Niacinamide 2 grams split through the day, Ca Pyruvate 2250 mg split through the day, Taurine 500 mg per day, Magnesium oxide 250 mg to 500 mg mid-day. Certainly take others but these are most recent and seem to be making a difference.