If you want to lower RH you can simply raise the temperature.
Following your diary's data, your plant will still be happy with a few degree extra.
Bottom line what matters is the best VPD vs. mold.
You seems to be on the sweet zone for now =).
Are you worry about mold? WPM? increase aiflow...
You talk about new dehumidifier... You have 2-3 weeks until it should be an issue (unless you have poor aiflow and air exchange).