New chain - remove the factory grease, yea or ney?

Nope, you're doing the right thing.
There will be loads of counter opinions, but that's all they are, opinions. Have a look at Zero Friction Cycling where this has actually been tested in a reliable and robust manner.

Silca have just released a hot wax system with a "strip chip" additive that allows you to remove the grease and hot wax the chain in a single step but you need to be able to hold the wax temperature between 120 and 130°C for ten minutes while it does its thing. Recently released so no independent testing on this yet other than opinion pieces.

Depends what you're going to do next?

If you're going to hot wax it, or keep it clean and regularly oiled properly (not just a splash on the surface). Removing the factory grease is a good idea.

If you're going to leave it until it goes orange with rust and crunches every time you apply a bit of torque to the pedals. Leave the grease in.

If you're somewhere in the middle, wipe the outside down with a rag soaked with a light oil to get rid of the surface grease, then apply a splash of your favorite oil as and when it needs it. At some point you'll need to clean it out anyway.

The factory grease is mainly there to protect during shipping and to act as a lowest common denominator lubricant. It's not very efficient, but it sticks like shit to a blanket and will last for months with light use and minimal cleaning.

There's quite a few comments on this thread from last week about the same thing:

https://singletrackworld.com/forum/topic/degrease-new-chainor-not/

Fair point, if it's going to be neglected, there's no point stripping it.

However, if someone already strips a chain of factory grease but is wondering if it's the best thing to do, I'd wager that are above average when it comes to chain care

I've been degreasing new chains for years but was concerned I was doing damage by doing so, so with recent mini-a11y bike build didn't bother. Resulted in cassette/chain/chainring all caked in a layer of sticky blackness after a couple of rides. Now thoroughly degreased and oiled properly. Never again.

I heard on a podcast ages ago, can't remember which, from someone that works at SRAM or KMC and they recommended leaving it on as the lube is really well penetrated into the chain so it makes sense to leave it there, perhaps give it a wipe or very slight light lube before first use then clean and regrease like you would normally.

I’d wager that are above average when it comes to chain care

Certainly not a bet i'd take. Lots of people do a half arsed job, all the time. Like stripping the factory grease and then applying a thin film of GT85/wd40/3in1 or a few drops of some ceramic laced and wax infused unicorn emissions at 50 quid a fluid ounce, then wondering why they've got no chain lubrication before they get to the end of the road.

from someone that works at SRAM or KMC

Only industry people i've heard up to now singing the virtues of factory grease were advertising, sales and marketing. Make of that what you will.

As i said up there ^^^^

The factory grease is mainly there to protect during shipping and to act as a lowest common denominator lubricant. It’s not very efficient, but it sticks like shit to a blanket and will last for months with light use and minimal cleaning.

You want a fast, durable chain, use the lightest/most suitable/favourite oil or wax for what *you* are going to be doing with it. The factory grease is a multi-purpose gunk that is doing several jobs, one of which happens to be "be an ok lubricant and rust inhibitor for a good chunk of our customers".

For MTB - Depends on conditions on the next ride:

The wetter and muddier it is the more likely I would be to leave it on.

For Road/Gravel - Just apply a couple of coats of White Lightning Epic no matter what.

Hmmm, reading through the comments on the linked thread above I’m no clearer! I think I’ll try cleaning off the surface grease with some ipa and see how it runs for a ride or two, any sign of gunky mess and it’ll be the degreaser