Using Activated EM to make more Activated EM?

I just recently learned about the wonderful world of EM and Bokashi, I just received my first bottle of EM1 and started a batch of activated EM. Everywhere I look online it is said that the motherculture can be used to produced about 20 times its original volume. It seems like in theory you would never have to buy EM1 mother culture again since you should be able to use the Activated EM to make new batches since its all the same Microbes and feeding process. But I have not seen online or heard anyone mention them extending their activated EM beyond what the original motherculture provided, is this just not a thing you can do or is it just something so obvious to everyone else that they do this and its just never mentioned?

AM I MISSING SOMETHING OR DO I HAVE A COMPLETE MISUNDERSTANDING OF HOW MICROBES WORK IN THEIR REPRODUCTION?!?! It would just be very nice if someone help me fill the gaps in my knowledge

You can try of course, though to be sure you'd need a microbiologist doing microbe counts.

For me, getting EM was a matter of inoculation. It got me a compost the likes of which I've never seen. It's become my putting soil, thus inoculating my garden. I've made aerated compost tea from it, to spray on my fruit trees. I've kept a bit to inoculate the following compost heaps.

I think that whatever microbes do well in those situations, will thrive, any others will die off, and those aren't any good to me anyway. Why buy EM again?

I don't buy EM (can't get it here) and start my culture using rice rinse water and then later milk and molasses. That gets put into bran, which later gets diluted down with wood shavings and used in my bokashi bucket. This way I end up making the EM serum maybe once a year.
I've heard of other people using dried milk powder, or molasses water.