I am not a lab scientist, just an old fart retired engineer that had to include lab work in/for my career.
I have used magnetic stirrers for 50yrs with many viscosity's.
Please allow me to convey my experience with how I converted it to e-juice.
I see the unfamiliar (new folks), buying units(new and used), and it is a smart thing to do. In my opinion it works better than a frother, or even a Badger 121 paint mixer, although I have/use a Badger 121 for certain applications, and not a frother. I am speaking of magnetic stirrers.
I see many mixers that use heat in one form or another to mix/steep, I am against it completely for my use. It's not so bad for any mix WITHOUT nicotine, but heat is liquid nicotine's enemy.
Each of us chooses our method, and some methods are based on 2-6+ years of usage/experience, and by reputable folks. I did not approach my method from any website [per se] that was e-juice related, nor from a youTube video, so many of you may discount anything I have to say, but I base it on experience.....and I am nobody special. I do own some high end magnetic heated stirrers, and if I use one for e-juice, I never turn on the heat. Mostly I use an analog mag-mix by GCA Precision Scientific  that is 25-30yrs ? old, and I just found another on ebay for $28 + shipping.
I mix in beakers [100ml] and put my stir bar in at the beginning, usually a high grade .75" 'capsule' , for a 60ml batch of juice. Add my VG and/or PG, flavors, then the nicotine on top. [mixing by weight]
I use beakers [science lab quality-flat bottom] because I can watch the scale readout while I drip ingredients and not miss the hole and make a mess, or touch the bottle and change the readout.
When all is in the beaker, I put it on the mag stirrer [DUH, DOH!] and start it slowly until I get a smooth spin on the bar. Many people have complained their magnetic stirrer won't create a vortex all the way to the bottom, or they can't get past a certain RPM......WTF for? Just get a smooth stir, a quiet stir, going, and don't worry. Use will tell you all you need to know about speed, size of stir bar, etc. When you doubt that it's mixing enough, take a flashlight [we all have a tactical led one, right?] shine your light sideways thru the beaker and see the air circulating.....it's hard to see without the light. Let it run for 30-40 minutes......the brown ring of nic that was at the top when you began will no longer be visible.[if you added your nic last- I use this as a gauge of sorts]. DONE MIXING at this point. Use your retriever to remove your spin bar and place it in your wash water beaker, stir it around manually, remove both [retriever and spin bar] and dry off. Pour your mix into bottles of choice !!!! BAM !! Your shit will be thoroughly mixed.
Friction, you know what that is [ask your wife when she is complaining that it hurts, big boy].(sorry, Ladies, to be crass) Why don't you need an expensive heated magnetic stirrer? [or a cheap one that won't last]
I start at room temperature [mixing]. When I get to the point of placing my batch on the stirrer, it is [for me] around 84degrees F.......after 30-40 minutes of stirring on a non-heated magnetic stirrer, the temperature is about 104degrees F any questions? It never bothers my nic, it thoroughly stirs, and when I shake it 2 days later, I get tons of air bubbles. No reason to trust me, I have no youTube videos, but try it this way, and all the other ways. Use your brain and decide for yourself. I have made tinctures and oil blends for decades and some REQUIRE heat, but I see no reason for heat making e-juice, but hey, did I mention, I am an old fart. If this above isn't clear, and you wish it was, contact me......I growl but I don't have any teeth to bite.
The pics [if I remember] show a small vortex at the beginning of a stir. You want a smooth, quiet stir, so you may need to turn it up to get started, but watch it closely, then turn it down as needed for a steady stir. It may look like nothing is happening, but shine a light thru the side and see the air bubbles. At the end of 30-40 minutes it should be cloudy when you shine the light thru it [pic].
I am not talking about thin juice either.......the pics are from tonight making Alisa's Bust-A-Nut @ 20PG/80VG
No negative heresay accepted [so and so said that......] I have too many critters to feed than chasing farts around the clock, but if you have a valid [adult] question.....shoot me [a line].