I do not have have the time to test it out at the moment but, have you tried a detonate action like a mine?
I'm pretty sure that's hard-coded to work w/ mine entities only. I took a look at a mine and saw there's also an explosion_ext, and the mine's weapon is an explosive. Problem is, the unit that I'm trying to make suicide bomb itself is getting the suicide ability through a squad_upgrade, and it's default weapon is a pistol.
However, I did manage to get a semi-working solution by creating a critical that has an off-map arty and make the ability trigger that off-map arty. Strange thing however, is that when the guy explodes, the explosion seems to trigger a few times not just once - Imagine it happening like a DoT.
So buggy this Tools.
Are you following the OKW buildings and their (former) self-destruct ability?
Originally, yes. But it didn't work, so I tried a semi-workaround explained above. But it's buggy.
EDIT: Also trying to do the death_action like what the Goliath would do when it's killed by something else. (Nothing I'm doing is working halp)