Flow temperature max. 27 degrees for glued vinyl flooring

Hello forum,

we want to glue down an approximately 2.5 mm thick vinyl floor (Joka Designboden 555 XXL) in our new build with underfloor heating and heat pump.
In the product data sheet it says (as with many other similar vinyl floors) that the maximum supply temperature of the underfloor heating may be max. 27 degrees.
I find that rather cool. Will the floor still be warm underfoot so that you can walk without slippers?
We like it nice and warm (in winter also sometimes 23 to 23.5 degrees). How high does the supply temperature of the heating have to be set then, or is 27 degrees supply temperature sufficient at all?
Or alternatively: Which other (vinyl) floor coverings would you recommend to us that can handle higher supply temperatures? Because there are houses with older underfloor heating systems that get hotter than 27 degrees.

Thanks in advance for your collective knowledge!

You are confusing something. The floor should not become warmer than 27 degrees, that is something different from the flow temperature of the heating.

what if the sun beats down at 35 degrees in summer?

I don't know, it never gets that warm here.

We never had more than 25-26°C supply temperature in the first winter to keep the house warm.
Usually rather below at 24°C. But I still find 27°C very, very tight.

The product datasheet states (as with many other similar vinyl floors) that the maximum flow temperature of the underfloor heating must not exceed 27 degrees.

Reading helps, quote product datasheet Joka 555 XXL:
"4. Warm water underfloor heating systems are suitable up to a maximum surface temperature of 29 °C."

For 29 degrees (not 27) you already need sauna temperatures. No idea what the flow temperature is, but it will be at least 40 ;-)