Build up a cold/dried layer of new polish on top of the dulled toecap. And then another. Leave it for a couple of hours.
Then start again to polish your toecap, using a clean smoothed damp polishing cloth, or better still a Selvyt cloth, dipped in water. Do standard small circles, with tiny add-ins of polish.
Run the toecap under a cold tap, use wet cotton-wool balls to finish it off.
Yeah, that does sound as though the leather has split.
I’ve never seen it happen as a result of polishing though. Scuffing, yes; and I once saw someone manage to peel the top layer of leather off whilst trying to remove a very bad paint job.
If it were me, I’d give the toecap a bit of a beeswaxing. Once hard that would most definitely make the surface smooth again.
BUT - That is a bit of an advanced technique and there may well be something else we can try.
I suspect that simple polishing and bulling might not cover it. At least not without a huge amount of work.
The problem is that if the leather has split (as it sounds) then it’d be like trying to polish suede.
A lacquer of some sort might help. But I couldn’t guarantee what it would be like to polish on top of, or that it wouldn’t just crack and flake off.
See if you can post that photo and I’ll continue to give it some thought.
If it’s not a large area then some perseverance with a brush to start building up a layer of polish in the rough section might help.
I have polished over scuffs before but it generally takes a bit of work if they’re deep or large.
The trick is to ensure that the polish must stick to the toecap leather, for the first layer. Then once dried-on a second/third layer, each of which tacks-on.
Because although you may think it’s the shoe you’re polishing, it’s actually the polish you’re polishing.
I’ve found that toecaps will bull better if you’re in a cold barrack block, or sitting outside. A warm centrally-heated house is ok for putting the polish on, but to get it semi-firm (to polish and not just smear) it’s better being colder…
If available, I used to put an ice cube in the polish tin lid, to ensure that the polish / water via the duster was as cold as possible. Made things quicker.
Modern-day people tend to live in half-cooked environments (houses at 19degC+ with central heating). Means the polish gets spread and thinned, instead of getting the chance to layer and set.
We need to bring back Dickensian room temperatures, at least for bulling shoes. Perhaps not outside loos, metal-framed windows, and frozen taps…that may all be a little-too 1970s
When I was on my stint of being “non-married,” if the ambient temperature was very high, I would put my shoes in the 'fridge to chill 'em down. That really made the process much quicker.
At Bruggen, with the 1950’s “single wall” Mess accommodation blocks & window frames with cracks that you could see light through, when winter arrived, chilling the shoes down wasn’t necessary! It was back to child-hood memories (only a fire place in the living room for years) & scraping ice off the windows in the winter mornings!
No luxury of mum / dad taxi service for me, I had a a 30 min walk to / from cadets; going there (Ryde, Isle of Wight) was easy, it was a slight up-hill then a long down hill. Took a bit longer (in hobnail boots!) on my way back.
There was a time (when we ran week long sessions covering various courses) that you’d open the fridge in the staff area to find beer and about 6 pairs of shoes/boots.