I wouldn't use that splitter, or anything that's not UL or CSA listed. I have had thisPhilips 3-way bulb for a little over three years and it still works fine.

I see thanks. (That's why my OP sought a safe similar one)

Not sure which exact 3-way Philips you're referring to (or what it costs) but what's your opinion of the below?

https://www.homedepot.com/p/Feit-Electric-50-75-150-Watt-Equivalent-3-Way-A19-Non-Dimmable-90-CRI-E26-Medium-Base-LED-Light-Bulb-With-Selectable-White-1-Pack-OM50-150-5CCTCA/336844045#see-more-details

I couldn't tell you as I have no experience with them. Did you click on the link for the Philips? that's the one I have at home. I am sure there are other good products out there, but I never tried them.

I don't think I noticed your link earlier, but just now i noted its clickable, so I'll take a look. Thanks!

I just researched, so now I think the link i posted above would not work in a 3-way lamp because its not dimmable.

Update: I now see that yours is not stated as dimmable either. So i'm not sure how well it might work in my Mainstays.

Based on what i read, it seems its advisable to either use (at the very least) a dimmable LED inside a 3-way lamp, or else a dimmable-3-way LED inside a 3-way lamp. But maybe it was just google's AI regurgitating nonsense as usual. I wouldn't know.

It was just google's AI regurgitating nonsense. A lamp made for a 3-way bulb has an extra contact at the base of the socket, and each turn of the switch selects one or more of these contacts. In the days of incandescent bulbs, 3-way bulbs contained two filaments, or if you want, two bulbs in one. By selecting one or the other filaments, or the two together, is how you got the three light settings. Any LED bulb designed for use in 3-way lamps will be made to work with your existing lamp without the need for dimming.

Thank you both for this enlightening info! So it's the term 3-way that counts, not "dimmable".

One more question:

How would a Non-3-way Non-dimmable LED bulb work inside a 3-way torchiere? Since I can't trust AI's search yields. We may have covered this earlier, but i'm in a rush as someone is picking me up, so if so, by all means disregard.

Only the intermediate, or "middle" setting would work. Suppose a 50-100-150 W bulb, when you turn the rotary switch, from the OFF position, the 50W setting is selected. Turn the switch one more time, and the 100W setting is selected. One more turn, and the 150W setting is selected. One more turn and it's back to its OFF position.

Since a non-3way non dimmable bulb has only one contact on the bottom and only one setting, it would work the same way it does in a non-3-way lamp, but you would have to turn the switch twice for the bulb to turn on, and twice again for it to turn off, since the "low" and "high" settings don't have a second filament, or circuit, to energize.

If that bothers you, it is possible in most, if not all, lamps, to replace the socket with a non-3-way socket.

I see, thanks again! Uh, would the following bulbs emit the full 150-watt of brightness inside a 3-way socket? I actually have two identical torchieres - one on each floor. And this is a twin pack, offering 4000K, which I think is good, though if I do sewing, would 5000K be preferable?

https://www.amazon.com/Equivalent-Bright-Non-Dimmable-2300lm-Brightest/dp/B0CCRRRFBB

There's also this 200-watt for approx. $12:

https://www.homedepot.com/p/EcoSmart-200-Watt-Equivalent-A23-Energy-Star-Dimmable-LED-Light-Bulb-Daylight-1-Pack-FG-04251/318065166

As well as GE 3-way for approx. $14 to $17

As well as Feit-Enhance 3-way for approx $21

Have you experienced EcoSmart one-ways or GE/Feit three-ways?

P.S. I'm not one to tinker electrically, as per your last paragraph.

Buy one 50-75-150 with selectable color temperature bulb. Experiment with the various brightness and color temperature (K) combinations until you find the one you like. Then buy a second, non-dimmable bulb with that brightness-color temperature combination. OR buy a second dimmable bulb with your preferred color temperature WITH the external dimmer switch.

The 5000K color temperature is extremely white, approaching blue. You may feel you're in an operating room.

I'm confused that you advise 75 for the mid-level option, whereas 100 seems to be much more popular for mid-level?

BTW granted I like 2700K-to-3000K (i own & used both those K's in 60-watt-equiv.)

However, I use a 75-watt-equiv. 5000K LED bulb at the working section of my kitchen because I need the high-definition for prepping food at counters.

By the same token, I probably prefer 5000K-daylight color for the 3-Way Mainstays torchiere in living room, as that's where i use my sewing machine.

Now i'll talk frank, even if houzz is intended as a decor-site:

My 5000K 75watt bulb is a bare frosted-bulb with no shade on it, other than that its "white" vs. "clear". No mason-jar, no Doric, or whatever they're called. Just one 75w-daylight bulb, screwed vertically (not horizontally) above the counters, enabling me to prep food. But my vision may well need to graduate to a 100-watt bulb in the non-distant future. The reason i've been sticking to 75-watt is concerns for fire-safety in case 100-watt might get too hot.

As for the section above my kitch-table, there's an old chandelier with five medium-base sockets, each containing a frosted shade wherein five 60-watt medium-base-LED-bulbs are recessed. The chandelier has a choice of 2-Lit-Up or 3-Lit-Up or 5-Lit-Up, by clicking one switch on its underpart.

Only at the kitch-table section of my kitchen do i prefer the warmer lighting.

"The reason i've been sticking to 75-watt is concerns for fire-safety in case 100-watt might get too hot."

LED bulbs don't get hot.

Uh, mine do, even in a socket that's plugged into a new GFCI outlet that a licensed electrician installed within the past approx. 10 years.

They all do to some extent, but they don't get nearly as hot as incandescent bulbs did.

I see... well a good way to find out, is if i'd screw a 100-watt-equiv above my kitch counters, then if it makes sparking noises, i guess that would mean its high risk.