You’re very welcome Ifan. This is a topic I’m sure will come up again, so I responded as much with a view to helping other people with the same question as addressing your specific situation.
One book I’d recommend without hesitation is Heat Pumps for the Home by John Cantor. While that covers a wide range of heat pump topics and is very much not specific to Underfloor Heating, it does have a few pages on UFH - and addresses driving UFH with a heat pump (rather than a boiler).
I’ve not read any specific ‘underfloor heating’ books myself so other people are probably better placed to advise, but publications from well-respected professional organisations should be trustworthy - for example Underfloor Heating Design & Installation Guide Book however watch out for publications which assume the UFH is being fed from a boiler, and add complex controls and mixing-down arrangements as a consequence.
Then there some videos from reliable, heat-pump-friendly heating engineers such as Heat Geek: for example: Under Floor Heating designing, spacing and balancing | Toolbox Talks
I very much expect you will end up with quite a number of loops / zones. Ideally you’d want to bring those together at a single UFH manifold, so you’ll have to consider if that might work or if you’d need multiple UFH manifolds.