I dressed once before using the alternate method in Season 7--turned twill.
I should have asked this question before I wound my two colored warps.

Unlike the turned twill, the project that I wound has many odd number color changes. (it's the Monkish towel draft)
ex: 3colorA 1 color B for 42 rounds. I kinda recall that we shouldn't separate pairs when spreading on the raddle.
in which case, what would be the best way to address my self made conundrum.

I hope this makes sense.

In this type of situation, I kind of just fudge it. For example, I just spread a warp that need to be six threads in each space of my raddle, but because I had warped four at a time, I instead alternated fours and eights across, which added up to the same thing. Keep those groupings together, and leave gaps as necessary to get the right or a close sett. That's the other thing you can do, is spread the warp for a close but not exact sett, if that works out easier. For example, spread on the raddle at 20 epi instead of 18 if it makes it easier to divide into the groupings you have. The full width won't be the same, but a small change of sett like that is manageable at the reed. We often change our sett after weaving a sample anyway, and don't adjust what is on the warp beam. I recently resleyed from 32 epi to 24 epi, didn't change the warp on the warp beam, and it wove just fine. So, yeah, my suggestion is to fudge the numbers so you get something that works for your groupings and is close enough to your desired sett. Happy weaving!