Just realised 2 and 3 is a prime number, so if you start with M1 splits into M2 and M3 it will just end there
. How about we add another rule, you can make it split into other modes (dont need to make it in sequence), but you cant jump modes too far, and you need to use every modes you jumped to.
This is to avoid jumping into non prime number modes too much and destroys the challenge. So what I mean is something like this
M1 splits into M2, M4
M4 splits into M6, M3
M6 splits into M7, M5
M7 is the biggest mode we jumped to, and we need to use every mode from M1-M7. You see in here there was no reproductive organ, so I think using this rule will be a challenging trait to have in your organism