There's no Geo measurement which would 'indicate' toe clearance - too many factors.
Besides Front-center, there is crank length, tire/wheel diameter, shoe size (and not surprisingly, shoe profile in the nose/toe area), cleat placement.
Toe-overlap has usually been a condition of 'road' type bikes, rare for what had been called 'touring' bikes.
There's a lot of history to this, and I won;t into that now.
But these days the problem is exasperated by bigger riders on smaller frames, general use of large tire sizes, and bike designers not adapting design for the overwhelming trend for use of large tires by a broad spectrum of riders.
Surprisingly, getting Front-center spec in manfacturer's specs is not a given. Specialized gives front-center, Trek does not... One can calculate front-center from the common geo specs given.
You need wheelbase, chainstay length, BB drop.
So, it becomes a personal investigation. For me, I generally ride 'Lg' commonly 56-57cm size in road frames, Have a 11/45 shoe size and the cleat is mounted well forward on the shoe sole , but Ball O Foot is positioned over the center of pedal spindle (I have a size 13 foot arch length with corresponding size 8 toe length... LOL! ) I still ride 700x23 or 25 on my road bikes. And use Sidi and Shimano shoes which don;t have a very pointy toe shoe profile. So, I can avoid toe-overlap if the
front-center is at least 590mm or a bit greater. If I were to go to a 28mm tire, it would be very, very close...
My own observations for a few years is that a front-center of over 600mm would accommodate tire sizes up to at least 42, possibly larger - for large feet (size 12 or under...)
I've owned a few bikes, over the decades, which had toe-ovelap, and none have ever been 'keepers' or considered a FAV... besides toe-overlap, there have always been other things which have made the frame less desirable...
Toe-overlap isn't even a 'discussion' when it comes to riding with flat pedals, because foot/shoe placement is usually all over the map...
For some, toe-overlap is not a consideration. I find it totally annoying and know it could easily be eliminated in frame design, so it's a none-starter for me.
Ride On
Yuri