The actual max firmware size for Linksys WRT routers

Ciao!

How are you?
How can I found the max size of the max firmware size?

https://wiki.openwrt.org/toh/linksys/wrt_ac_series

Openwrt shows 1900ACS 34MB (2 : rootfs1. rootfs2) shows:

The 3200ACM shows 74MB (2 : rootfs1. rootfs2):

So is it the actual max firwamre size I can build?

Thanks!