Keep in mind that the term " lacquer thinner " is as meaningless as the word " beer "

" beer " doesn't tell you if it's a lager or ale yeast , what grain was fermented , if hops are added , what the alcohol content is etc .

You can just hope it's served cold . 

Paint manufacturers formulate their lacquer thinner to work with the type of resin employed in the coating  , and it's tailored to provide the best performance - evaporation rate  - for the most likely environment it will be used in  , temperature and humidity-wise .

Here's a brief overview of acrylic resin differences in paint  : https://coatings.specialchem.com/selection-guide/acrylic-resins-for-coatings

Lacquer thinners can be only alcohols , only ketones or a combination of the two with other solvents possible .

The Mr Color utilizes both a ketone  ( like acetone , but not ) which is a pentanone and more than one alcohol

You can see in this MSDS : https://manualzz.com/doc/8122791/gunze-mr-colour-thinner--t101--102--103--104-

This formulation is designed to work with the acrylic that they have selected to use in their paints .

It will not be compatible with all acrylic paints  , but will be compatible with those labeled " lacquer acrylic " like AK's Real Color or Tamiya's for example .

The lacquer thinner you find in hardware stores / big-box stores is usually used for cleaning purposes and is literally the kitchen sink of solvents .

The  Kleen Strip brand is mostly methyl alcohol and acetone but also toluene , ethyl acetate ( surprise ! ) and alkanes and cycloalcanes that they don't define  , but pentane / cyclopentane and higher for sure . Who knows  , it's the kitchen sink ...

And of course a glycol ether since it works so well though it's very toxic .

https://redwavetech.com/wp-content/uploads/2021/06/Klean-Strip-Lacquer-thinner_SDS.pdf

Can you use that in Mr Color paints ?

Yes  , but it's certainly far from ideal .

So in short  , the reducer must be compatible with the resin employed in the paint .

There are also modified alkyd resin paints  -- the majority of enamel spray paints -- that are engineered to work with these various solvent formulations for the same reasons .

For cleaning you can use whatever solvent you want that will dissolve the cured resin at hand  ,,, obviously  taking into account the material you are cleaning will not be damaged by the solvent(s).