Crippling lag when mob with wide hitbox pathfinds up a hill

Partner Rank: 2

Verification builds: 1.16.0
Regression builds: None

Summary: When a mob with a very wide hitbox pathfinds up a hill using the tempt behavior, the server takes a tremendous hit. Interestingly, the attack target behavior, with seemingly identical pathfinding, causes no lag whatsoever. It also appears to be the case that lag occurs from other behaviors such as random stroll.

Impact: This makes an upcoming map pretty much unplayable in its current form because of the performance. We have several options to avoid this issue, such as reducing the hitbox size, but none are ideal.

Repro Steps:

1. Download the attached world
2. Press the button on the repeating command block on the left labelled "tempt"
3. Hold the bone and stand at the top of the stairs
4. Observe crippling lag grinding the server to a halt
5. Kill the mobs
6. Press the button on the other repeating command block labelled "attack"
7. In survival mode, hold the bone and stand at the top of the stairs
8. The new mobs pathfind just fine, no lag at all

Expected Results: No lag in either case

Observed Results: Extreme lag in the first case

Screenshots/Videos attached: Yes

Notes: Early insight about why this happens or potential advice on how to better work around it would be very much appreciated.