Using modifications to the original pattern, following same mods as in my “purple patchwork” blanket here (lots of notes, including joining method with pictures):
https://www.ravelry.com/projects/toriellen/crazy-patchwor...

Video of joining method: https://youtube.com/shorts/19UKXjzf8Vs?si=CyqVW05hdVgv4cu0

Relevant notes here:

To start, chain 4, join to form a ring, ch-3 (counts as first dc), then proceed with 2 dc into ring, chain 2, around (4 3-dc sets with 4 chain-2 corners), join to top of starting ch-3 with sl st. At the beginning of round 2 of the same color, use a chain-3 as the first dc of the next round.

In general, for each round, you dc into each dc, and in the corner (pulling tall!!): 2 dc, chain 2, 2 dc.

When finishing off a yarn color (in one of the inside colors), I didn’t join the last and first sts together with a slip st… instead, I first broke the yarn and pulled the yarn all the way through (like the first step of an invisible join in the round), then threaded the yarn end with a needle under the top (both loops) of the first st from the previous round (from front to back). Then I wove the yarn into the back-side of the last dc, this seemed to make the join most invisible to me.

When joining the new color in the next round, start in a whole new corner, and start with a “standing dc” stitch. I always started in the corner with the first of the 2 dc (first one being the standing dc stitch), 2-ch, and 2 dc. This made it much easier to keep track where the beginning of each round was, and keeps the fastening-off-of-yarn in the very last round near a corner.

At the end of the very last round, join to the top of the first st from the previous round with a slip stitch (going through both loops of that st), break yarn, then weave the yarn through the sts from right to left along the top until you get to a corner, leaving at least 2 square’s width length of yarn (plus a bit more for weaving) for sewing later.

Total sts on a side (including 2 corner sts -- one on each side):
10 round: 41 (39 dcs + 2 corner sts)
8 round: 33
6 round: 25
4 round: 17
2 round: 9
Useful info when planning out the joining edges… sometimes you need to work two sts as one to make the number of sts add up along a side.

8 round + three 2 rounds = 33 + 27 = 60
8 round + 6 round = 33 + 25 = 58

Final dimensions after 2 rounds of mostly dc border: 20”x67” (was probably a little stretched when I measured it).