I did consider making my own large format emlarger some time ago. After some research and much innovation I decided that my efforts in making such a device was not viable in time and efficiency. The main problem was to make the contraption rigid enough, beit horizontal or upright. With the drastic reduction in prices of large format
enlargers I consider the time would be better spent searching for that bargain second hand. Nevertheless, I do have a sympathetic understanding of your reasons for being so innovative. You will, of course use a suitable close calibrated lens for enlarging work
to be of a high standard, not all large format camera lenses are. Good luck.