Efficient approach to generate list of combinations with no repetition

PeterBartholomew1 thanks great solution too! I adapted it to be able to return not just 0,1 values, but the actual values of the x-array. I combined it with COMBIN.SETE I provided in the UPDATE section of my question as follows:

COMBIN.SETPB = LAMBDA(x, m, LET(
  y, TOROW(x),
  n, COLUMNS(y),
  k, 2 ^ SEQUENCE(1, n, 0),
  h, SEQUENCE(2 ^ n),
  p, SIGN(BITAND(h, k)),
  f, BYROW(p, LAMBDA(p, SUM(p))) = m,
  z, IF(FILTER(p, f), y, NA()),
  WRAPROWS(TOCOL(z, 2), m)))

since it has been proven the most efficient way so far to convert 0,1 values to x-array.

Note: I guess you are using Advanced Formula Environment Add-ins, defining the formula via the Names tab, I converted it to a LAMBDA function, so it can be defined in the Module tab.

I tested for n=19, m=10, for the input array set:

SEQUENCE(,B1,10,10)

I run it several times and in all cases > 4secs. I defined the following performance function:

PERFORMANCE.SETPB = LAMBDA(x, y, LET(start, NOW(), out, COMBIN.SETPB(x, y), 
  IFERROR(HSTACK((NOW() - start) * 24 * 3600, out), ""))
)

and calling it as follows:

=PERFORMANCE.SETPB(SEQUENCE(,B1,10,10),B2)

maybe you have in mind a more efficient way to do the mapping from 0,1 values to x-array values, so we can improve your approach.

Note: Since it is based on a binary function BITAND which has a limit, the maximum number to represent is (2^48)-1, therefore m <= 48.

Thanks