I grew Ailsa Craig last year and they get to a fair size when sown early. Piccy here at the start of the thread a few posts down.
https://chat.allotment-garden.org/index.php?topic=131334.0They don't get as big as Globo, but are still very mild and juicy, so I would persevere with them. OH loved them as whole roasted onions as a side dish, or baked stuffed onions as a main dish. I think I would have a mutiny if there were none this year. He is usually indifferent to most of my veg seedlings in the house, but spotted the onions and was happy to see them in progress
I also clump sow spring onions. Works well
I do beetroot, turnips and baby leeks the same way.