Are you sure? I just tried that: import 2 clips (each a few seconds) put them both next to each other, double click where they meet: you get an error message that says not enough frames at clip end to apply the mix.
That’s with version 24.5.2 on a mac
If I trim one of the two clips then it works, also contrary to what the doc says, I can trim by a small amount and it does work (for example 2/10 of a second), which is great!
In any case, it’s fairly easy/fast: trim the end of the left clip, butt the clips, double click.