yes
with *-git
pamac/yay donwload app sources for read last app version : so pamac/yay can update or not only after download all *-git
ps: If *-git is disabled with pamac, there is a good reason ! it is better to do a --devel once a week
not *-git
pamac/yay, for all aur packages, send one request to aur (use rpc) for get last version - aur responce is very small so the request is fast
is not pamac but aur 
compile aur app is very long if pc is not very powerful
For the aur update process, there is no difference between all aur helper rpc, git clone, makepkg and pacman -U (or makepkg -i)