interesting. Post gestational diabetes I lived off salads to keep my hba1c at 30. After introducing back legumes, and some more carbs, it went to 33. After falling off the bandwagon completely in the last year and eating a carb heavy diet and mass amounts of choc and ice cream, it was 34. I would be concerned if it was 38, to me a clear sign I’m heading in the wrong direction.
It's entirely a matter for you about where you want your BG levels to be.
Mine has been bouncing around between 34 and 38 for around three and a half years and I'm OK with that. The variation is within the acceptable error on the A1c test - which (depending on which professional body you listen to) is somewhere from 3% to 6%.
Your result range of 30 to 34 could likewise be covered by a steady figure of 32, (plus or minus 2mmol/mol) assuming 6% testing error.
At an HbA1c of 38, the fact is that you or I would still be lower than most of the population, including diabetic and non-diabetic. If the trend of your A1c is upwards, you might decide to do something pre-emptive about the increase, although the current level is not in itself problematic.