Ussualy people used cuda runtime api it is different library incompatible with cuda driver api.
I was try to solve 32bit limitation few years ago as soon as the first cards with more than 4GB memory appeared.
But unfortunately this limit could not be overcome.
And do you need to utilize all the memory?
On my 2080ti already at -w 27 the hash rate drops from 570mkeys to 81. While at 3070 everything is fine.
So you need first to check how your hashrate will decrease with increasing parameter -w.
here is with cuDeviceTotalMem_v2

some question i have for my understanding

does memory allocation in gpu maks difference in speed?
how to know T, P and b optimal value for my card (3080)?
what is W and -htsz role?
and what is item size ?
can i occupy more ram in computer to give some speed boost as i have 128GB memory ? if yes how can ?
return correct 64bit values but it is only information it is didn`t help to solve all limitation in cuda commands.