help with pattern

Sleeves (work 2) size 7 needle Cast on 42 sts work in rib pattern for 4" end on RS inc row: p1, m1p,p1, k2 last 2 sts p1, m1p, p1 53 sts. Change to size 9 needle and pattern as follows: 1st row p3, tw2 last 3 sts p3
2nd row k3, p2 last 3 sts k3 (Continue in pattern as set increasing 1 st at each end of next and following 6th row to 77 sts. Taking extra sts into pattern.cont straight until work measures 18".) If I continue in pattern for the increases won’t this mess up the cable tw2 stitch in other words they will not be straight?

Take the increased sts into the pattern as knit or purl sts until you have enough sts to work the tw2 with an extra edge stitch. In other words, you may have to wait until you’ve increased 3 sts on an edge before you can p1,tw2, p3 etc.
Keep the alignment of the tw2 as you increase. You may have p1 or p2 at the edge, it doesn’t matter. The important thing is that the tw2 sts don’t jog out of line.
What pattern are you making?

Thank you this makes sense. The pattern I am making is Elation in Artesano Aran