Interesting report. An open universe (curved) does not provide the same Hubble time using the H0 constant either (and perhaps a different value for H0 too), some age of universe calculations 2 billion years or more younger than the flat universe model.
COSMOLOGY CALCULATORS Most reports I read at popular science sites that date the age of the universe as 13.8 billion years old use the flat universe calculations - (supporting inflation). Otherwise age problems arise as well as ages of various star clusters like globular clusters or stars dated via uranium decay and the Hubble time. We also have the z number conversion for redshift and distance from Earth. Look-back time is one thing (e.g. 8 billion light-years distance). Where the object is in the universe is very different compared to the z number conversion commonly reported. Presently the CMBR blocks the view of objects that may be there - way beyond so remain unverified