I cannot make the formula spill dynamically in 2D

I need some fresh pair of eyes to look at the following Excel formula. I’ve got the following formula, where I cannot seem to make it spill down dynamically. The formula currently spills to the right correctly. If I change B5 and C5 to B5# and C5#, the formula does spill down (and to the right) correctly, but the values are incorrect. Can someone help me? Below is the formula. Note that B5# and C5# spill down the same exact number of rows with 1 column each and D$1# and D$2 spill to the right the same exact number of columns with 1 row each. I would appreciate your help. Thanks.

=LET(
deviceInstall, B5,
deviceRemoval, C5,
tcoStartDate, 'Deal Information'!B$6,
tcoEndDate, 'Deal Information'!B$7,
tcoStart, D$1#,
tcoEnd, D$2#,

installMonthsFrac, MAP(tcoEnd, LAMBDA(end,
    TRUNC(YEARFRAC(deviceInstall, end) * 12) +
    IF((DAYS(EOMONTH(deviceInstall, 0), deviceInstall) + 1) / DAY(EOMONTH(deviceInstall, 0)) = 1,
        0,
        (DAYS(EOMONTH(deviceInstall, 0), deviceInstall) + 1) / DAY(EOMONTH(deviceInstall, 0))
    )
)),

removalMonthsFrac, MAP(tcoStart, LAMBDA(start,
    TRUNC(YEARFRAC(start, MIN(deviceRemoval, tcoEndDate)) * 12) +
   IF(DAY(MIN(deviceRemoval, tcoEndDate) - 1) / DAY(EOMONTH(MIN(deviceRemoval, tcoEndDate), 0))=1,
      0,
DAY(MIN(deviceRemoval, tcoEndDate) - 1) / DAY(EOMONTH(MIN(deviceRemoval, tcoEndDate), 0))
))),

IF(
    deviceInstall >= tcoStart,
    IF(deviceInstall < tcoEnd,
        installMonthsFrac,
        0
    ),
    IF(
        deviceRemoval < tcoEnd,
        IF(deviceRemoval >= tcoStart,
            removalMonthsFrac,
            0
        ),
        IF(removalMonthsFrac < 12,
            removalMonthsFrac,
            12
        )
    )
)

)