More of a map design issue than a balancing issue.
I found the best way of avoiding TML crush games is to not play certain 10x10km team game maps, or at least be very vigilant that a TML is strong on these maps. The kind of maps where one person rushing a TML slightly outside their base can hit the core Mexes of 6 opponents. I still very vividly remember one open wonder game where someone rushed T2 upgrade and build a TML on full t1 eco, and proceeded to kill like 20k mass worth of mexes and HQs.
On larger maps (say 15x15), or even 10x10s with spawns far enough apart that you need to establish at least some mapcontrol before building TML (like plateau of arracis, or adaptive millennium), I find the TML perfectly balanced.