I was thrilled to see my Monstera's new leaf unfold, but now I just wanna toss it
For each new leaf, there should be one of those infamous axillary buds (note spelling). Sometimes they're not easy to find, but they're easily recognisable.
If you want to try a cutting from that gigantic Monstera, I suggest you to look for tips on "air layering".
This summer I was given a cutting with 3 very big leaves -smaller than yours -, and the few roots were not able to get the water it needed.
It took a solid 2 months for it to make enough roots, and I had to cut a leaf to slow transpiration down.
As far as I'm aware, variegated Monstera were grown from seed just once; during an experiment on mutations induced by gamma radiation.
The other seeds are a scam.
SP - Kinda ridiculous? Have you checked the price for a variegated adansonii recently?