Ok. Not sure how large this site is but i would immediately start logging upon arrival at site. A minimum of 5 minutes before the first GCP (use Stop&Go) . I would keep logging during flight and at the end visit one or more of the GCP just as a quality control.
Stop logging when you leave the site. And keep the rover in a tribrach or other support to let it record good data during the entire session.
With PPK and Stop&Go, you should not have any issue with such short baseline and the RS2.
Depending on the site, this should give you enought time and data to process accurate enough data.
I’d agree with @TB_RTK’s: as you’re working with RS2 on somewhat short baselines, there should be no issues with whatever time period you choose. However, as you now mention that the area is wooded, your averaging time and your overall results will depend on the observational quality.
So it’s actually hard to recommend any specific time period. If you have a chance to check out the data quality before the survey - just recording a raw data log there and assessing it in Emlid Studio, - it’d be great to do so. If not, I suppose you can use a few minutes interval: it’s the most general duration you can choose.