I have like 2600 schematics ... and I really don't want type /#convertschematic *filename and set it to active ... Is there a faster way?

What, why do you have so many schematics?
Most schematics need to be set up individually either way - like what biomes do they spawn in, and at what height at the very least - even if you don't consider adjusting the blocks to use natural floor and space blocks to integrate into the terrain better. So you'd need to individually configure each structure either way, making a mass conversion command pointless.

The only approach that would make a bit more sense is a placemod - style simple generation, which I have considered in the past, but am currently not implementing (yet?).