As a food technologist, this is a very interesting idea. Here are some off the cuff embellishments.
Boiling the dough to make it tougher sounds reasonable, but may result in a sticky surface. You might need to roll the boiled dough in flour to dry it out a bit for easier handling.
Mixing the dough thoroughly in mum's cake mixer helps develop the gluten and make the dough tougher. Most "cake" mixers have a dough hook for mixing dough, and use this or you may bug*** mum's pride & joy.
Use strong flour because it has more gluten. eg Champion or Pam's "High Grade". It's intended for making bread.
It might be possible to buy gluten from a supermarket, but a quick Google suggested it's not very common. Extra gluten (say 2%) will make the dough tougher. It's available from food ingredient suppliers. e.g
https://www.mpbio.com/nz/gluten-10-kg
I've always used MSG (monosodium glutamate) in my berley, at around 1%. You can buy 500g bags of MSG from Chinese shops e.g. Tai Ping, Wah Lee, etc. MSG is a fish attractant.
Using fish oil will improve the fishiness of the dough but will also weaken it, so only use around 0.5 to 1%.
About 1 to 2% gulp juice to replace some of the water in the dough is an excellent idea - this won't harm the toughness of the dough as much as fish oil.
You will need to freeze the dough if you have any left over, otherwise it will rise (wild yeast) and/or go mouldy. Alternatively, add 2% vinegar (or 0.2% citric acid powder) and 0.1% potassium sorbate (
https://www.haurakihomebrew.co.nz/products/wine-stabiliser) or sodium benzoate for a longer shelf life at ambient temperature.
I'm sure other food techies will have other improvements.