Alright so I'm a diamond 3 ADC and I know how level 1 teamfights are. When you have a strong lvl 1 teamfight, u should look to invade. It gives you a good chance for some easy kills and potentially denying the enemy jungler a buff. If you time a late invade, you can potentially set behind both the jungler and the enemy laners that get dmg'd from the invade (they'll come to lane with lower hp or be forced to recall). Having a blitzcrank is always an indicator that theres a high chance for an invade. Generally, you want to have the champion with the hard CC to lead the invade; they'll be able to immediately engage on the enemy on sight with their cc, providing your teammates with enough time to follow up and engage.
Now I've mentioned good times to do an invade on the enemy jjungle but what about bad times or times where the invade can fail horribly? You do not want to do an invade on the enemy when your level 1 teamfight is much weaker. If you don't have vision out, you won't know if the enemy is also doing an invade on you so a potential worse cast scenario here is that you invade the enemy jungle but u dont see anyone so your team decides to go back into their jungle. The enemy team warded your jungle and they were hiding in one of the bushes near your buff and they force a lvl 1 teamfight on you when they have the better positioning and vision for the fight. Likewise, if the enemy team goes for the counterinvade and camps a brush that your team facechecks into, your team is at a disadvantage and can easy the lose the fight. **Level 1 vision is super important **and your team needs to be grouped and positioned properly for the invade.
The level 1 invade is a good idea in general but you should understand how execute it properly and what potential dangers you can face if you commit to it.