Make sure the cables are well secure and covered with 10mm of levelling compound or what ever the ufh company spec Sent from my iPhone using Tapatalk
Most water based are good to go over ufh but double check the tech sheet or give them a call if unsure
You can use pretty much anything really but I prefer Latex like NA or 1200 just so I know it has a better chance of bonding
Renovation for me , nice to have the fibres to keep it all together especially as it’ll be a good 16mm to get that 10mm cover over the cables