Absolutely. Their triggers can ebb and flow. There are times when they have more resources to deal with the world around them so their tolerance is higher, they found something to focus on that they enjoy etc. Other times they don't have the capacity within them to deal with what's going on around them and they melt.
I have found that the key is to catch them as they start to rumble. So that is BEFORE you get to the meltdown stage. Each child has their own quirks. When my son starts to rumble (that means his energy is building) he frowns, or grunts. That is the time that I need to catch it and help him problem solve, redirect, whatever I need to do to help diffuse the situation. If you don't catch it in the rumble phase then the child moves on to the Rage phase, which basically means a meltdown. Once you're in meltdown mode, you can't make time go backwards. They have to work through all of the energy and emotions they have and get it out. After Rage comes Recovery. Each child is different in how they recover. My son has a tendency to sleep or need his weighted blanket, time alone, a snuggle on the couch.
When you melt it takes so much energy out of you, and given that sometimes just being in a room with another person can cause so much overstimulation and trigger you constantly, can you imagine how exhausting it would be to be in their shoes?
It's tough. Good luck riding the roller coaster. You guys will muddle your way through it. It's one of those "learn as you go" things.