I've dug through some of the code attempting to understand how the redstone dust limits power 15.
I've found something in RedstoneWireBlock, but I'm not entirely sure how to create a new dust/item that would allow for a signal bigger then 15.
i've also worked & created a new Redstone Block, that does act as a redstoneblock w/ the overrides on  

public int getWeakPower(BlockState blockState, IBlockReader blockAccess, BlockPos pos, Direction side) { return pw; }

with pw being a value past 15.

I'm ok with it not being possible, but I'd hope to come across a solution that would help make my ideas on my own mod a bit more ... interesting (allowing a compressed redstone block to reach further out on a dust)

On 3/21/2021 at 2:09 AM, diesieben07 said:

You'd have to make your own system completely separate from redstone, because everything in redstone assumes that 15 is the max. A redstone wire only has 16 states (0-15), a comparator only has 16 states for its input power, etc.

Actually comparators are not the limiting factor, they do support over 5 bit (16 state)  values, and can do comparing and subtraction with them, but its the redstone dust that limits signals to a max of 15, and even overwrites higher signals. repeaters and torches don't effect or change signals, but they will react to any signal over 0, and only output 15 when on. Not you need to overstack in order to see comparators reading and outputting higher value, or use command block success counts in order to "count" or set a value over 15. The only problem is you cant read those signals with Dust as talk about before, but you can use comparator subtraction in order to augment the signal down and then see the result.