ST_MakeEmptyRaster makes in geovalue worth 10000 and such when I want normal geodata

Question

I have here made a demo of my attempt turn points on a map with values then use St_interpolateraster and than send it back as geojson. It returns values and they are interpolated well. My problem however is that I am trying to shape it geometricly and than add a little border the like it came in but it just wont work so I can use it on mapbox. My attempt on the shaping. My code is greatly inspired by this: https://www.crunchydata.com/blog/waiting-for-postgis-3.2-st_interpolateraster When using everything works fine

ST_AddBand(ST_MakeEmptyRaster(200, 400, 10, 10, 0.01, -0.005, 0, 0), '16BSI')

So the problem exists within this line or before

ST_AddBand(ST_MakeEmptyRaster(width, height, upperleftx, upperlefty, pixelsize), '16BSI')

DROP TABLE IF EXISTS PointTest;
DROP TABLE IF EXISTS ValueTest;
CREATE TABLE PointTest(geog geography(point), point_id INT); 
INSERT INTO PointTest(geog,point_id)values ('POINT(10.5 9.5)',1),('POINT(10.5 9.5)',2),('POINT(10.5 8.5)',3),('POINT(11.5 9.5)',4);
CREATE TABLE ValueTest(temp INT, point_id INT);
INSERT INTO ValueTest(temp,point_id) values(1000,1),(1000,2),(500,3),(500,4);
WITH myvalues AS(
    SELECT
    ST_Collect(ST_PointZ(st_x(geog::geometry), st_y(geog::geometry), "zvalue"::float)) as geom
    from (select geog,temp as zvalue from PointTest s inner join ValueTest p on s.point_id=p.point_id) as sources
  ),inputs AS (
    SELECT
      500::float8 AS pixelsize,
      'invdist:power:3:smoothing:2.0' AS algorithm,
      ST_Expand(geom, 10000) AS ext
    FROM myvalues
  ),
  sizes AS (
    SELECT
      ceil((ST_XMax(ext) - ST_XMin(ext))/pixelsize)::integer AS width,
      ceil((ST_YMax(ext) - ST_YMin(ext))/pixelsize)::integer AS height,
      ST_XMin(ext) AS upperleftx,
      ST_YMax(ext) AS upperlefty
    FROM inputs
  ),
 interpolate AS(
SELECT ST_InterpolateRaster(
    geom,
    'invdist:smoothing:2.0',
    ST_AddBand(ST_MakeEmptyRaster(width, height, upperleftx, upperlefty, pixelsize),'16BSI')
) as geom from myvalues,sizes,inputs)

SELECT row_to_json(fc) 
  FROM 
    (SELECT 'FeatureCollection' as type, array_to_json(array_agg(feats)) as features 
      FROM 
         (SELECT 'Feature' as type, 
                 st_asgeojson((gv).geom)::json as geometry, 
                 row_to_json((SELECT props FROM (SELECT (gv).val as value) as props )) as properties  
            FROM 
                (SELECT 
                    ST_PixelAsPolygons(
                       ST_SetValue(
                         ST_SetValue(
                             ST_AddBand(
                                 (select geom from interpolate), 
                            '8BUI'::text, 1, 0),
                        2, 2, 10), 
                     1, 1, NULL)
               ) gv 
          ) json
    ) feats 
) fc;