There are a couple in this show.
We don't talk about the first one in ep.1, 'cause that's a boy on girl kiss, and we don't talk about those here.
The second one is in ep.5 (right around the end)
In this one an android kisses another android to activate it (same stuff happens in the first clip, but with a human boy, this time is girl on girl tho)
Now we get to the ones I'm interested in
Ep.16
In a dream, a villainess android kisses the protagonist and gets a power-up (she grows in size and gets bigger boobs/butt, so it doubles down as a breast expansion/age progression thing if you are into that)
Mostly comical, but still good:
https://www.deviantart.com/noogm/art/Steel-Angel-Kurumi-ep-16-Transformation-Kiss-931723674
Ep.19
I need you guys to fact check me on this one.
An evil android (a very boyish one at that) forces a kiss on the protagonist, this causes her to achive her"true form", and the protagonist gets knocked out from the kiss.
I guess it's energy drain? If they gave an explaination about it, I didn't read it, and I'm not going to honestly.
Here it is tho:
https://www.deviantart.com/noogm/art/Steel-Angel-Kurumi-ep-19-Transformation-Kiss-931724227
(Full clips as always in the description)
There might be more in the following seasons