I like the idea of printing a holder, for the part-it holds the part laterally and indexes the new printing. I would maybe model it and slice it separately. Then model and slice the text as a first layer thing. It is important the slicer doesn’t think the text is floating in the air, or it will interpret it as a bridge, and do weird stuff. Don’t use skirt or brim on text slicing. I’m thinking print the holder, keep the bed warm. Raise the extruder up out of the way. Get the plastic piece warm on the heated bed. Put glue stick on the part and stick it to the bed in the holder.
With the extruder cold, slowly bring the extruder down until it is the right height to print, could use a sheet of paper between the part and the nozzle as a feeler gauge. Now the Z is at the right height. Bring up the text G-code. At the beginning of the G-code, edit the homing command,
G28, to be
G28 X Y, no Z, so it won’t home the Z-axis. Also, delete or comment out
G29 auto-leveling if present. Then type in a line
G92 Z.1, this spoofs the position of the Z-axis so the printer thinks it’s at zero plus the thickness of your sheet of paper (.1 mm). Add in a move to prime the nozzle, after it is heated
M109, right before it starts moving.
G1 E10 F400. Then
G92 E0, then a retract move
G1 E-2 F3900. This is right before it starts moving, with a long series of
G1 commands. Note, ignore the prime, retract thing if your G-code already includes it. That should be good to print.
Dial down the speed and be ready to catch the plastic squirt from the prime move with some tweezers, you could even hold something flat and metal under the nozzle as it primes to simulate having a surface to build up pressure. Immediately after the prime, be ready to micro-step the Z-axis to dial in your first layer as it starts printing on your part. Turn up the speed if everything is going to plan.
You could pull the filament out of the extruder and do a dry run if you’re worried about the part. Or print a couple in case the first one gets messed up.