Mail Merge function for Plotter/Printer (AxiDraw V3/Bachin T-A4)

This was asked before, but need the same services. Business purpose. Print multiple letters/envelopes. I need a solution for an AxiDraw V3 and Bachin T-A4 plotter I just purchased. Inkscape or whatever else application which will be more suitable to this task. I'm using G Sheet and Autocrat add-on to generate PDF/G Docs A5 mail merge to print multiple letters with individual names & then Multiple envelopes with different addresses. I'm using my own handwritten font created with [login to view URL] with variations of characters and would need to have each mail looks handwritten. It means each letter has to come within a range of different spaces between rows, paragraphs, words randomly by applying written script on G Doc/Inkscape or others. The range of course has to make sense. The printer is been used just to role down the paper on the plotter. So it has to work like this: - I put two A5 letters close to each other on A4 template in Inkscape or others - Create multipages with other pack of letters - Setup the plotters to start writing on 1st piece of paper - Plotter goes to the start position and delaying - Once writing is finished, printer has to roll down the blank paper - Plotter starts to write next letter from pack. - Cycle repeats.