Nice work with the update @rutgerkok, I'll report any bugs I find when I get chance to test it. Can't say I'm not disappointed to hear that about the forge version, it hasn't worked properly for any of the 'major' versions of Minecraft since 1.7.10 and even then only because PeeGee fixed most of the bugs.
Some observations @AgentOre (Biome Bundle maker here).
I noticed in some of your screenshots you seem to have generated some map (ocean biome) without BiomeBundle and then installed it and generated chunks without deleting the previous world, this is why you have this problem.
As for feeling like there is lots of ocean (in bbundle at least), this is simply due to the seed and starting point. Biome Bundle maps are about 70-80% land but the oceans are not small (and contain unique biomes), some seeds start you at the centre of a huge ocean, and it could go on for thousands of blocks, however when you do find a continent it will span 20k blocks or more sometimes and contain hundreds of biomes without an ocean in sight.
Here is a seed that does exactly what I mean, if you started in the centre of this map and headed in one direction it could appear that there is nothing but ocean:
I've also seen seeds generate a map this size with no ocean at all. Try a few different seeds if your starting location is not as you would like.