Gridfinity Pen Holder - Faster, cheaper

Thanks @BigPeanut for the model. I did some minor manipulation on the model to in gain a few milimeters of volume and define localized infill areas to reduce the material and print time as much as I can, and keep the print stable.There are infill only were necessary: to support flat surfaces and the back and side tall walls. The main chamber infil is about 5% density, only between the external walls and the cylindrical holes, to keep the walls in shape. I did test to print without those, it works, but the walls became wobly to touch. The model is the same as published by @Peanut (https://makerworld.com/en/@BigPeanut)https://makerworld.com/en/models/1314663-gridfinity-pen-holder?from=search#profileId-1349498This version is overengineered on BambuLabSlicer to reduce the time to print and material. single wall, and minimal infill.You can print at Sport mode, or even ludicrous, if you are brave enough (at least after layer 26, then the bottom part is all connected).PETG is recommended.