The ref paper cited and abstract provides some interesting info to geek out on
"...We present JWST/MRS (rest-frame infrared) spectroscopic observations of the quasar J1120+0641 at z=7.0848 (well within the epoch of reionization). The hot torus dust was clearly detected at λrest~1.3 µm, with a black-body temperature of Tdust=1,413.5+5.7−7.4K, slightly elevated compared to similarly luminous quasars at lower redshifts. Importantly, the supermassive black hole mass of J1120+0641 based on the Hα line (accessible only with JWST), MBH=1.52±0.17×10^9M⊙, is in good agreement with previous ground-based rest-frame ultraviolet Mg II measurements."
A SMBH of 1.52E+9 solar masses, diameter about 39.48 au across, compare this size to our solar system from Sun to Pluto. Redshift 7.0848 using cosmology calculators provides distance (look back time distance) about 13 Gly,
https://www.kempner.net/cosmic.php
Resolving this black hole diameter at about 3.99E+9 pc, close to 9.9E-6 mas angular size. The comoving radial distance in GR expanding space places the object well beyond the 13 Gly distance used for most reporting.
Edit correction. 1.52E+9 solar mass BH about 60 au across and angular size about 1.5E-5 mas, I used 1 billion solar mass BH initially. The abstract reported 1.5E+9 solar mass BH.