I've never seen that before.
I have a HotShot I use for up to 16 oz. but you have to add water to the unit manually each time you use it. We use it for instant coffee, tee hot chocolate, etc.
What I found interesting, when reviewing the specs and users manual on that unit, is the fact that it's only something like 750 Watts. My 16 oz unit is 1450 watts and cost $20.
I know different application and uses but I would question the recovery rate. I see it hold 2/3 gallon, so you have some reserve but as you use it cold water comes in cooling what's already there so I assume the flow rate has to be pretty slow if you plan on using more than a small amount at a time.
I know there are a lot of small point-of-use units for under sink mounting but I suspect they are set up with a much lower max. temperature. Common for bathrooms sinks.
The last one I installed was Everhot brand. Seemed to work well and the customer was happy with it. After installation don’t put your fingers under the stream of water to see if it’s hot yet. I found out the hard way it was blazing hot.
I have several customers who have the Little Butler instant hot water system from Franke.
They seem to last about 5 years, sometimes as long as 10, before rusting out.
Then they leak and cause trouble.
And the water lines can also rot out.
But they are great while they last.
I usually see them combined with a water chiller, and both are fed charcoal and ceramic filtered water which is fed to a hot/cold dispenser at the kitchen sink.
Any system you choose, put a catch pan under the water tank, and at least one water leak alarm in the pan or under the sink.
I have been using ISE insta hot both in my home and installed dozens over the years.
I have also taken them apart over the years.
They used to be crappy with copper tanks and went through years of development and they really improved. Today they are stainless steel tanks with a good warranty.
You have to use their dispenser because their connectors are made to work together.
There are no user replaceble parts on either the faucet part nor the tank.
The filters that come with them are really worthless. We throw them away.
Even the mfrs reps refer to them as "beginner's filters". Don't bother using.
Depending on what your water source is, a good charcoal bock filter will likely be fine.
I think the Multi-Pure is great, but so are many others.