Create an MVT with properties from PostGIS and store in MVT cache table.

mvt_creation.sql

INSERT INTO dev.natural_earth_countries__mvts (z, x, y, mvt, tile)
  SELECT
    5,
    10,
    13,
    ST_AsMVT(tile, 'COUNTRIES', 4096, 'geom') mvt,
    ST_MakeEnvelope(
       ${-m + (x * r)},
       ${ m - (y * r)},
       ${-m + (x * r) + r},
       ${ m - (y * r) - r},
       3857
    )                                        tile

  FROM (

         SELECT
           id id,
           pop_est,
           gdp_md_est,
           gdp_md_est_edit :: NUMERIC / (pop_est_edit :: NUMERIC + 1) * 1000 AS gdp_pp,
           (pop_est_edit / st_area(geom_3857)) * 1000                        AS pop_dens,
           ST_AsMVTGeom(
               geom_3857,
               ST_MakeEnvelope(
                   -7514065.6274999995,
                   3757032.8137500007,
                   -6261721.356249999,
                   2504688.5425000004,
                   3857
               ),
               4096,
               256,
               TRUE)                                                            geom

         FROM dev.natural_earth_countries

         WHERE
           ST_DWithin(
              ST_MakeEnvelope(
                 ${-m + (x * r)},
                 ${ m - (y * r)},
                 ${-m + (x * r) + r},
                 ${ m - (y * r) - r},
                 3857
              ),
              geom_3857,
              ${r/4}
           )

       ) tile

RETURNING mvt;