I had this one (https://www.t-falusa.com/Kitchen-electrics/Fryers/Ultimate-EZ-Clean-Fryer/p/7211001726?scc=fryers) that has a container for the used oil. It worked just fine till it died after 5 or so years. It was still a pain to clean though as the fry bin and basket were pretty big and the exterior also got sticky/oily.
I'm back to cast iron, thermometer and a nice oil filtration (overpriced, but works well - https://www.amazon.com/gp/product/B0123J1S60?psc=1). It ends up being easier cleanup and pretty much just as easy to use. Bonus that I can use different size CI/enameled CI depending on how much I need to fry. I just have a big 1 gallon jug of oil that is deemed "fry oil" that I keep the oil in.
1) From my pre-tallow days, the best home fryer I found was the T-Fal FR8000: https://www.t-falusa.com/Kitchen-electrics/Fryers/Ultimate-EZ-Clean-Fryer/p/7211001726?scc=fryers. It has a built in strainer with a valve that opens as the oil temperature drops from dying temperature to room temperature, and the straining process let me reuse the same oil longer than if I hadn't strained it. It also has an integrated storage container that solves the biggest problem of home frying, which is storing large amounts of oil. If I overfill it and/or don't store it perfectly level, the storage container leaks a bit, but that isn't hard to avoid. Unless I insisted on traveling with it to family get-togethers at vacation homes, which I stubbornly did. I used mostly Costco Avocado oil, which is probably heresy on this thread, but at least is more MUFA than PUFA (I think?).
2) I am 98% sure that the self-straining mechanism and/or storage mechanism on that fryer will not work for my tallow, because it will solidify either before it goes through the strainer, in the storage container, or somewhere in between. I have never verified this because making a batch of tallow is not insignificant work, and I don't want to have to chip one of all of these vessels, but I'm pretty confident in that it's a no-go. Also, +1 on the comment that solidified tallow + a narrow, horseshoe-shaped heating element would lead to pretty uneven heating - at least during warm-up - and potentially some sections of tallow getting heated to way above their smoke point.
3) Now that we are all-in on tallow, we fry french fries once a week (Friday Fryday) as a family. We have two cheap 8 qt stockpots: we keep the tallow in one, and after cooking we let it cool down a bit and pour it through a strainer into the other. We use the strainer component of this bundle: https://www.amazon.com/dp/B0123J1S60, but any fine-mesh metal strainer would work.
4) +1 on the recipes that say to fry twice and chill in between. We have found that freezing in between the two frying sessions creates a nice contrast of crunch and fluff. These days we'll spend a couple hours on a weekend doing a "first fry" on a whole costco bag of potatoes, then freezing in ziplock gallon freezer bags. On Friday Fryday we just take out one bags for the second fry. Lasts a month or so.
5) We're still playing around with the thickness of the fries to get the fluffiest interiors, and the target temps for the first and second fry. We current get to about 325 for the second fry, a little lower perhaps for the first fry. Not an exact science and sometimes we cook to a color not a temp.
6) Sweet potatoes work almost as well.
7) agreed that these are incredibly addictive.
8) agreed with Potential_Limit_9123 that french fries cooked in tallow have not proven to be an effective weight-loss aid. I've been taping my belly a la the original Brad posts, and the periods of biggest drop in circumference were when I went as low as possible on carbs. Always <50g/day, and usually <20g day, mostly from red wine and a square or two of 85% dark chocolate. When I added back some fries and cocktails, the progress stopped and occasionally reversed. But you have to live and these are fun indulgences.
I bought this funnel/filter a few years ago, and it has served me very, very well for a variety of applications. Cooking oil being one of them: https://www.amazon.com/Chefs-Planet-130-Multipurpose-Filter/dp/B0123J1S60/ref=sr_1_28?dchild=1&keywords=Mason+Jar+Funnel&qid=1608652730&sr=8-28
As far as gadgets go, my new favorite is a strainer/funnel gizmo that screws directly onto wide-mouth mason jars and has an attachment for smaller containers. It's awesome for straining stock, making syrup, straining fry oil, making my yogurt into Greek yogurt, etc. This thing has made life a lot easier with some of the more pain in the ass tasks in the kitchen.
https://www.amazon.com/gp/product/B0123J1S60/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1