It is interesting the different experiences, materials and methods that everyone has with home pcb making.
Initially when I first tried it back in the 1970's I started out with ferric chloride and had little trouble, using a combination of Dalo pens and rub on transfers. One day the ferric chloride became unavailable and I had to use ammonium persultphate and it gave a poor result, with much more undercutting of the tracks and the ink even seemed less resistant to it. So I went back to ferric chloride. But it might have been a "one off" experience that put me off it.
So perhaps its easy to be put off by one off events, when really one technique or one product might be equally as good as another, if you persisted. Which may explain why there are so many different materials and techniques still around.
Over the years though I realized I could never get my home pcb's as good as a professionally made one, so for any project that I want like this I bow my head to my pcb maker and cough up the $. But if I want something to have a "home made" look, on occasions I still make one myself, with iron on film and ferric chloride.
Jaycar still sell a pcb ink marker pen that is pretty well identical to a Dalo pen:
https://www.jaycar.com.au/etch-resis...-blue/p/TM3002