RTK - Static, independent?
Expected practice for RTK boundary surveying here is observe and then 20mins plus later re-obseve from a different or same base after re setting up (isolate set up blunders etc.). This gives you results in the field you can keep working with vs having to go back to office to process static.
For suburban work the actual repeatibilty (not the spec sheet single standard deviations) can be under 10mm which is fine but often gets into the 15-20mm which even when average the obs still appears a bit sloppy when you put the total station over the top.
I'm thinking that an alternative would be to do short static obs (5+ mins, lines all <1km) which generates a more precise measurement than RTK and at same time take an RTK obs which could be used to complete fieldwork and as a check on RTK. Once back in office static can be used to tighten up the calcs.
Setting aside environmental and setup factors, would you consider a RTK and a static measurement observed at the same to be independent measurements?
The twenty minutes was a rule of thumb to change the satellite configuration. That isnt necessary anymore. You can easily change the configuration since there are so many up. The base point should always be checked against known points.
Response based on Trimble gear and configuration:
In this situation I would use base/rover RTK with infill. Meaning both base and rover are logging static data. For troublesome points I would take two 180 epoch shots on the corner with a force break in base RTK solution between observations. Then I would take a separate 15 min (at least) static observation and process that shot independently at a later time and merge/average in TBC once back home.
But if critical, just use the gun and shoot it in.
Changing your rod height enough to make a re-observation or stake-out to the stored observation is also a good strategy to reveal a multipath solution. You would need to vary the height more than the L1 wavelength. A foot or a foot and a half should do it. You may get a different mulit-path solution, but you could almost never get the same mulit-path bust with a different antenna height. Still may not tighten up things enough to give you the comfort facto you seek, but it would reveal a bad fix pretty quick, if that even happens in these four-constellations in view days.