New LACP on VCMP enabled f5 pair

I can't comment on the HP side of it as I haven't worked with any of the HP switches in years, but I would create the new LACP trunk side by side the old one, then move over the VLANs to the new trunk. If you don't, you'll need to disassociate the VLANs from the current 1Gb links, delete the 4x1Gb trunk, then go back in and associate them with the new 10Gb trunk. If things go awry, your backout is a bit tougher too.

If you were switching from access to trunk ports, you'd have another hoop to jump through, but this should be pretty simple.

You shouldn't have any issues with the guests. In their eyes it's like they uplink for the switch they're on is unplugged for a few minutes. They're just bridged to the interfaces. Basically they'll have no connection while you migrate them (whichever way you choose) but once they're reconnected on the host, they won't care what they're connected to on the host. You can do all sorts of things with the guest's vlans, rename them, etc. As long as the tag in the host matches the guest, you should be OK.

Either way you choose to do it, put together the tmsh commands so you can just copy/paste it into the CLI and make sure to do a save sys config at the end. It's a bit of extra prep work, but a lot better than clicking through 30 VLANs to move them around.

i.e.

create net trunk my10gbTrunk { lacp enabled lacp-mode active interfaces replace-all-with { 2.1 2.2 } }
tmsh modify net vlan vlan28 { interfaces replace-all-with { my10gbTrunk } }
tmsh modify net vlan vlan29 { interfaces replace-all-with { my10gbTrunk } }
tmsh save sys config

and backout of

tmsh modify net vlan vlan28 { interfaces replace-all-with { my4x1gbTrunk } }
tmsh modify net vlan vlan29 { interfaces replace-all-with { my4x1gbTrunk } }
tmsh save sys config

Good luck!