Using a combination of "Reference storage" and "FILT sharing storage", I invented a way to store BCD data onto FILT:

Reference storage:

I use a single bit to represent a number that would otherwise take up mutiple bits; the rightmost 4 bits represent 1, 2, 4, and 8; the next 4 bits to the left of those represent 10, 20, 40, and 80; the remaining 2 bits to the left of THOSE represent 100 and 200.

FILT sharing storage:

With multiple large binary number values now represented as single bit values, I can use "FILT sharing storage" to store the smaller numbers on a single pixel of FILT.