As Bill, I tend to overbuild.. Glue the hell outta everything..
However, on the Tiger 60, just added two .40's and was done..
Did make wing joiner longer..
Twin Stix, welp, that thing is a tank.. It is 9 years old and still has original covering.. And it is only over powered twice as much as what is called for..
Tiger II on table.. WAY over built.. But then, will be WAYYY over
powered..
Advance 40.. ZIP, nada, nothing to make stronger. That is to be a simple twin bash.. Slated for two .40LA type motors..

Something to remember is if you are that concerned about wing
loading.. Add wing span which will lessen wing loading and make plane more docile, as someone noted previously..
Another area most people seem to overlook are the tail surfaces..