It does heat the water enough for a single user Daz I used one for years m8 with decent batteries they work well,it’s worth buying for the cabinet alone if you got that cabinet for 500 notes you could go on the Webasto site and buy the complete kit for that for around 1200 notes.
That cabinet doesn’t look anywhere near as heavy as mine was from Varitech the cabinets they put there heaters in are like Sherman tanks way over engineered and like I say are seriously heavy,although it’s a single user you’ll still need 2 batteries that are well looked after and it will supply water hot enough to crack glass trust me.