I’ll have to voice my opinion on this. Multipath is not good for any type receiver. The best receivers/software can pick out the good clean signals and derive a reliable fix. That’s why they cost more.
Have you ever stood under a large tree when it’s raining ? The rain isn’t as bad as standing out in the open. Same principal in GNSS signals… You will receive fewer/less quality signals under the tree. Any kind of multipath with any kind of low cost receiver is not good.
If you are concerned about multipath in an area you are locating, you’re probably are already in a bad area for GNSS observations. Without proper validation/field location procedures for any located point, you are taking a big gamble on the supposed “fix” solution using GNSS equipment.
Closed observation loops using local short baselines are your friend. They will tell the true value of your “fix” on the located point. Without some kind of verification, whether by terrestrial/GNSS PP loops, you will never know what the true accuracy of your located point is.