MetalLB + map new external IP to sub-domain == profit.
Read some of the other comments: it's not about your control plane. All you need is multiple external IPs which an IPAM module/plug-in can provide (MetalLB, Cilium and maybe Kube-VIP: I've never used it).
Ingress controllers like Traefik come across as LB services to IPAM modules like MetalLB (I've never used Kube-VIP but I suppose it's the same story). These plug-ins assign IP addresses to these LB services.
You can assign a specific IP to an instance of an "outward-facing route" with labels. I don't remember technical terms relevant to Ingresses because I've been messing with the Gateway API recently.