Most 7-food destination squares will have a maximum of 3 of one other resource type. So another option is to build 3 resource plots (not 4) to a maximum of level 12 before doing the Exo-Tenaril. However, personally I think this makes the process unnecessarily complex.
It is VERY easy to find short-hop Exodus squares to match the beginning configuration of human, elf, dwarf and orc cities -- because there are lots of these square types, either once starter cities now abandoned or created by the system to be new city spawns in the future.
So if a new player has managed not to upgrade more than 3 plots, more power to them, but if they haven't and this is a concern, then it is an easy matter to find a short-hop Exodus square to match their starting square. The Exo-Tenaril process can be tedious, and there's no need to add extra "rules" to remember like "don't upgrade more than 3 of any plot even if you happen to have them." (That is a handy suggestion for people who are planning Exo-Tenaril, but when advising new players I try to walk a line between what might be theoretically ideal and what is too complicated to be any fun.
This also happens to be why I don't advise all new players to do Exo-Tenaril. It can be a great thing for those who have the patience for it, but it can also be very burdensome and result in attrition as players lose interest and give up because all they do is build a gigantic warehouse.
I often think that more established players have forgotten what it's like to be new in Illy and that it is easy to lose sight of the big picture in pursuit of shiny tricks.
I honestly think it would be better for the game if the Exodus-Tenaril process were determined to be an exploit and if Tenaril were available only to the initial capital.
Off to the suggestion forum for me.