i think it's interesting how ectobiology is being used as a symbol of the regressive and the repetitive; it is literally the science of "making babies out of ghosts", so in other words the art of remixing existing ideas over and over again (its literal main purpose in Sburb: creating multiple groups of slightly different kids, literally 'paradox clones', so it can attempt to reproduce the same way again and again until something works). Dirk thinks making a new species out of old ideas via ectobiology is the way for Homestuck to keep going forever. Jade thinks having a new kid without ectobiology is the one way to break the monotony, even if it's literally with one of the same eight people her family has been tied up with for the past 5000 years.
this does have further implications worth discussing when viewed through a queer lens. what does it say, for instance, that these characters appear to view pregnancy as the only way to have a "real" baby, and making a baby in a lab as the "fake" way? even Kanaya seems to echo this sentiment when she expresses resentment over her race having been forced to reproduce with machines. we have been talking a lot recently about how aspects of paradox space that may seem queer or liberating on first glance - quadrants, for instance - are actually just veiled tools of the patriarchy, and it's true that the same could be thought of ectobiology; for one thing, Sburb only seems interested in pairing men and women, even when they lack any sexual chemistry in reality. so maybe it is queer and liberating that Jade and Rose, by eschewing ectobiology altogether, have earned the place of being the first gay couple in Homestuck to make a baby together, breaking that streak. but because Homestuck^2 inherited by necessity the Epilogues' positions on sex and gender, which at times come across as deeply un-queer and un-liberating, it's also true that Jade and Rose have only been allowed that opportunity because of some fluke of their biology. nothing seems to have been truly liberated from the way it was before; if two people on Earth C want to have a kid regardless of their own biology, the very machines which are being painted as regressive seem to be the only option they currently have. and this has ramifications for the building of interspecies families just as much as it does nonheterosexual ones, which is a major concern not just for the subjects of Jane's xenophobic regime at large, but also for a great portion of Homestuck's own core cast