If the assets in UK's balance sheet are "money in HU's bank and payment processor accounts that we're entitled to" then it would be difficult for UK bailiffs to do much. The only physical assets that can be identified from company's house information are only identifiable because of the prior charges on them in favour of leasing businesses.
UK's legal addresses are Luton airport and an address in a townhouse in London used by other unconnected overseas aviation businesses. I don't think any of us are aware of them having the sort of meaningful presence at Luton Airport of the same nature as that which, for example, bailiffs looking for easyJet could have fun with. None of the directors are British which would even make Orders To Obtain Information difficult and expensive or impossible.
I assume the individual claims are small, with the result that meaningful winding up proceedings would in almost all cases require a number of the CCJ holders to work together in order to meet financial limits (and share legal costs). This would succeed, but would be almost impossible for any individual to co-ordinate (even without attempts to frustrate; eg paying off the petitioner but not supporting creditors). It would have to be done by the sort of solicitors that texted and called people about "the accident you were injured in that wasn't your fault, the overdue essential repairs to the property you rent from a council or social landlord and / or the money you're owed by WizzAir". Anyone that got into organising this would want a significant cut of the amounts recovered :-(