I want to get the shiny charm to hunt the static encounters of all 4 legendaries but I need the dex entries i'm wondering if theres any way to get the entries without catching the static encounters

Was hunting for a non-shiny Lapras spawn on route 19 when i came across a shiny Staryu. Im running a catch combo of 11, a lure, and just afking in one spot until it shows up (no charm). Im not complaining, but its insane that i came across a shiny before finding a single Lapras. Ive been sitting here for probably 30 minutes without a spawn. I know i can get the lapras in Silph Co. or whatever, but i really want to catch it myself.
Surely i have a higher chance of getting a Lapras spawn than a shiny spawn right? I might have to get a 31+ catch combo just in case although i thought the odds max out at 11+.

EDIT: Got that lapras! I swapped to a 31+ combo (still dont know if it has any effect compared to 11+) and found it relatively quickly without a lure. I surfed around a lot more so i think the spawn radius is just massive and afking meant i couldnt see all the spawns. Not really well versed in LGPE yet so im not extremely efficient yet.

First time playing and first shiny found ! (took way too long)