When to consider The Wall ready to be used? (Devo+WHR builds)

I hope this quite long post will help new Wall users and curious early players like me to have a clearer idea about the Wall.

So, I'm developing The Wall offline, means I respecced it after unlocking a few labs, and I'm working on labs: particularly I'm focusing on Thorns, Health, Regen. I'm fading Fortification because of its labs cost.

Using a Devo build, unequipping the Wall grants me more coins than with an underdeveloped Wall on.

With the Wall on, and an Devo build, Coins are less because in order to use Wall Thorns, which are percentage of Tower Thorns, I need to set regular Thorns to 101%. This means that when the Wall goes down, my Devo build is not working anymore, cause I consume enemies instantly instead of packing them around the tower, thence losing like 5-10x the coins.

I have a Mythic WHR, which has proven to keep me alive once my trash wall used to go down.

The goal is to make my Wall strong enough that once it goes down, my run ends, because my WHR will be redundant, dying under Vampires disabling Regen.

I wonder when shall I consider my labs ok to re-engage my Wall and make it useful to make my runs actually longer. Considering what kills me now is Vampires blocking HP Regen, and being the Wall immune to that, I think this happens when you have Wall Regen near 100%.

A lesser value should be ok if Wall Thorns were equal to regular Thorns, but being way less powerful, like 7-10% right now, instead of 34% used for devo, this lets enemies accumulate more damage before getting killed, so a stronger Regen is needed, which on the other side can be compensated by immunity to Vampires.

Another thing to be considered is that the quantity of enemies spawned will be less, because Wall Thorns take a longer time to kill them, so at a certain point you reach the limit and gotta wait to kill some of them to make new ones spawn. This affect Coins.

Devo WHR users: at what point did you find the Wall to be prolonging your runs and increasing Coin income?