Quick test of Zebes' lava behaviour:-
The lava's first rise is to just below the stage, where it rocks up and down for a while. Then it falls, or it rocks up to covering the depressed parts of the stage. After this, it falls. The next time it rises, it repeats the above procedure, but after that, it covers the main stage and rocks up and down for a while. After this, it goes down, rocks a bit below the main platform, comes up and covers the main platform again, then rocks below, then finally drops.
The next rise has it cover half of the lowermost platform. After that, it rocks, and it will either cover the whole of the lowermost platform, or fall. After this comes the million dollar question: will it cover the second platform? It seems to not be an overcommon occurrence, because it generally stops with the lower platform. However, it happens, so do not stand over there with false confidence.
Occasionally, the lava does a fake out, that is, it falls quickly and it appears to defy the rough pattern. However, it will stop below the main stage, and and start to go back to where it was again with the rocking etc.
So the lava on Zebes isn't as 'random' as it seems to be, so players can to a certaind egree 'predict' what the lava will do next, and accordingly move to the next safest place ratehr than having to try to 'camp' the uppermost platform. WHen the lava does cover 95% of the stage, it lasts for seconds, and it does a reverse rocking effect like any other fall. This means that you will nver actually get suckered by the lava, it gives pkenty of warning with the earthquakes etc.
Well, this is admittedly no Hyrule nado, but this is a lot more predictable, so gameplay can easily account for this general pattern without too many changes. WHile you're duking it out, keep a corner of your eye out at the lava and the earthquakes, and you'll be able to guess what it'll do next and react accordingly. I hardly think a split second of having just one platform matters too much, especially when all characters can easily stay airborne that long if they don't want to have a King of the Hill game at the top at the cost of having to predict your opponent.
Basically, if you keep track of the lava(not very hard to do), you don't need to adopt different measures to counter it, just rise to the next safe platform and continue the fight. The only real uncompetitive instance is when the top platform becomes a micro-FD, and even that can be avoided without too many issues due to the short duration.