The generator matrix

 1  0  0  0  1  1  1  X  1  1  0  1  1  X  1  1 aX  1
 0  1  0  0  X  1 X+1  1 (a+1)X (a+1)X+1  1 (a+1)X+1  X  1 aX+a (a+1)X+a+1  1  0
 0  0  1  0 (a+1)X+1  1 (a+1)X (a+1)X+1 aX+1 aX X+a (a+1)X+a a+1 X+a+1 (a+1)X+1  X X+a+1 aX+a
 0  0  0  1 a+1  X aX+a+1 aX+a+1  a aX+a aX+a aX+a+1 (a+1)X+a+1 X+a aX (a+1)X aX+a+1 aX+a

generates a code of length 18 over F4[X,sigma]/(X^2) who´s minimum homogenous weight is 43.

Homogenous weight enumerator: w(x)=1x^0+252x^43+732x^44+420x^45+432x^46+1980x^47+2634x^48+2076x^49+1296x^50+5508x^51+6051x^52+5364x^53+3792x^54+10836x^55+8595x^56+5556x^57+2160x^58+4464x^59+2946x^60+408x^61+15x^64+15x^68+3x^72

The gray image is a linear code over GF(4) with n=72, k=8 and d=43.
This code was found by Heurico 1.16 in 2.86 seconds.