If you have all the "uci commands" in a text file, apply them manually yourself using ssh on a clean image and see if it has the desired effect on your config.
Maybe you have to split the uci parts in multiple sets of commands and commits with some sleep time before it may finally put everything to its place. Than you may wrap a shebang at the beginning of text file and then you have a script.
#!/bin/sh
/bin/sleep 5 #wait 5 seconds
#some commands may need absolute/global filesystem path
#/usr/bin/exampleprogram argument
#/usr/sbin/exampleprogram argument
uci command a
uci command b
uci commit
/bin/sleep 5 #wait 5 seconds
uci command x
uci command y
exit 0
Test that script on a clean image with ssh/scp, than finally include the tested/working script in the asu image builder recipe. However I'm not sure if you just copy the uci commands from your script in that asu webpage or also the actual beginning and ending shebang/exit0 syntax. See other users with more experiance: Custom script to run on first boot using linux builder - #15 by u251