image builder 生成固件， repository 每次都要 update 的问题？

[qazwsxkevin]

ibuser@testser:~/ib$ cat repositories.conf 
# Remote package repositories

src/gz openwrt_core https://downloads.openwrt.org/snapshots/targets/ramips/mt76x8/packages
src/gz openwrt_base https://downloads.openwrt.org/snapshots/packages/mipsel_24kc/base
src/gz openwrt_kmods https://downloads.openwrt.org/snapshots/targets/ramips/mt76x8/kmods/6.6.35-1-4e8d6c272de9c18291da74bc95245884
src/gz openwrt_luci https://downloads.openwrt.org/snapshots/packages/mipsel_24kc/luci
src/gz openwrt_packages https://downloads.openwrt.org/snapshots/packages/mipsel_24kc/packages
src/gz openwrt_routing https://downloads.openwrt.org/snapshots/packages/mipsel_24kc/routing
src/gz openwrt_telephony https://downloads.openwrt.org/snapshots/packages/mipsel_24kc/telephony

# This is the local package repository, do not remove!
src imagebuilder file:packages

#option check_signature
ibuser@testser:~/ib$ 

已经把 option check_signature 注释了，
每次 make 时，依然还会还会为了 Building package index 去官服做下载 Packages.gz ，做 Updated list of available packages ，有时候前后相差 30 多分钟，同一个 ipk 似乎 checksum 变了，ipk 要重新下载。。。

请问，这个方式是否可以不要这样？ 就以当前的状态去做 make?