If the heel slip is not too bad, maybe try something like this that you put under the tongue of your shoes, slightly pushes your foot back against the heel. I have some in a couple of shoes that gave me heel blisters and they worked well for me.
7 Pairs of Felt Tongue Pads Cushion for Shoes, Size Large https://www.amazon.com/dp/B0030MC67A/ref=cm_sw_r_cp_api_glc_fabc_UYZbGbHYRR0E5?_encoding=UTF8&psc=1
I'd be interested to see a picture of your lacing, because Alden should have the right length, based on the ideal spacing of the quarters when tied. You might have a slightly lower volume foot/ankle, necessitating a tighter lacing. Adding a tongue pad on the upper part of the tongue can help fill in some of that space.
All that said, if everything feels good, and they're just dangling down a bit too much, then slightly shorter laces will do the trick.
If you're concerned about the lace gap, add a tongue pad. I use these. They stick-on, so if you don't like it, you can remove it.
I essentially have flipper feet-I need a wide toe box, yet narrow heel/ankle, so depending on the model-I add a tongue pad.
I had a similar issue. Compared to my Redwings my couple sets of 1ks just feel like they support my heel area less. Try http://www.amazon.com/gp/product/B0030MC67A/ on the tongue if they slip a little. Will keep you from having to wear hot heavy socks. Helped mine a lot
A tongue pad might do the trick.
I don't think you can easily modify the shaft to reduce the size, but you can easily add tongue pads on the inside of the shaft to take up some room. They're cheaper than dirt and easy to test fit.
Another potential option is to skip Chelseas altogether and go to something like a Jodhpur which can be tightened at the shaft more easily.
use inserts that stick to the tongue. They prevent heel slippage better than the heel stickers.
like these: https://www.amazon.com/Pairs-Tongue-Cushion-Shoes-Large/dp/B0030MC67A
In my experience, heel grips are terrible. Tongue pads or insole liners are better options.
Were you fitted in that shoe by one of the staff there? Sometimes heel slip is a symptom of the shoe being a poor fit.
I have thin heels so heel slip has been an issue for me, too. As stupid as this sounds, I think I have largely solved it by tying my shoe laces more effectively. I now have shoes that feel very voluminous in the heel area that do not slip when I walk.
The two rules are:
The laces have to be tied tight enough that it is snug on the top of my foot.
My heel has to be firmly pushing back against the inside of the shoe's heel area while I am lacing them up. If there is any "slack" it allows the foot to move around. I accomplish this by actively pushing my heel back into the leg of the chair I am sitting in as I tie the shoes.
A couple of notes about getting the laces tied snug on the top of your foot:
Obviously if you go too tight it is going to be uncomfortable later in the day.
If you are tying your oxfords like this, I would switch to a different method like this one that cinches closed more easily.
When you tie a pair of oxfords closed, is there a v-gap between the facings like this or are the facings coming closed like this? If they are completely closed, it is possible that is happening before you can get them snug. If you think that might be the case, you could try tongue pads. They would fill out some volume to let you get the laces tighter and also help push your heel to the back of the shoe.
You can try a couple of things. Some people use tongue pads to add a touch of volume so the vamp is a little more snug. I've also tried Superfeet Black insoles which are good for about 1/2-1 size and also give really good support. They don't slide around at all and are very comfortable.
I use the tongue pads you can get off amazon. These.
Yea I missed it initially but somehow it magically came back in stock and I was able to get a pair. Honestly I have no idea how this happened.