For sure - I casually looked at OpenWRT on x86 and it seemed (on the surface at least) to be more fiddly than opnsense. Updates and handling storage/partitions appeared to be more unclear to me. But that was probably just me, I didn't dig too deep into it.
1. Use the ext4 image and extend the main partition to the full size of the disk. This requires a lot of "fiddling" later in case of upgrade (as parent wrote).
2. Use the combined squashfs image and don't touch the image layout (no resizing, keep the ~100 MB free default / partition). Easy upgrade experience like other embedded devices (get image, open ui or ssh, upload, flash, reboot, done). Oddly, this isn't made clear by the official Wiki at all and the simplest option.
IMO, the best configuration is running your x86 box with Proxmox and run the squashfs OpenWrt in a VM. There is no need for more than 100 MB of space and if you need to install so many packages or apps, better create another VM and use a standard Linux distro. It will also be more standard for many apps to be installed on a full fledged OS instead of the custom OpenWrt layout.
You only need 2vcpu and 256 MB of ram to run standard OpenWrt at 1 Gbps (SQM included if you have a recent CPU). The rest of your box ressource can be used for anything you want.
