Hone and run it, or machine shop?

Torque plates are not at all the same as the mains torqued in place; they will change the roundness of the bores near the head bolt holes, near the top. Having said that, street engines rarely get that treatment, and it is not any issue of note, that I am aware of.

I raced 4 bangers, turbo and N/A, for a long time in more endurance type of racing (rally) and it seems to work out fine without torque plates, but the engines get rebuilt after maybe 1000-2000 full-blast miles, and HP is not at a premium like in an all-out drag race or circle track engine. However, excess blowby due to out-of-roundness was never any issue that I ever observed, and the Opel 1.9L blocks will go out-of-round by as much as .003" in the #4 cylinder when everything is torqued.

I worry more about taper (constant flexing on the rings) and clearance (piston wobble), than torque plates. New pistons is also a plus IMHO, with good tight ring grooves, to keep the rings stable and flat, and you get that without or with the re-bore.

And while your calipers may be accurate to .0005", that is not the same as calibrated to .0005". It won't effect your relative measurements (taper and out-of-round) but it can throw your absolute numbers off (piston-to-bore clearance). That is a good reason for a machine shop to always ask to have the pistons in hand before boring.... it removes some/all of the absolute accuracy errors in the measuring equipment.