So I've noticed that the endpoint: https://sessionserver.mojang.com/session/minecraft/profile/ has weird API rate limiting behavior. If requests are sent on an interval basis (at rates of 6, 30, 60 requests per minute), then between seconds 48 through 60 of every minute, the response is a HTTP 429 error (regardless of the number of requests sent from seconds 0-47 of that minute / the request rate). At other request rates such as 20 per minute, there does not seem to be any issues from my testing. 

This behavior makes no sense (from my testing). I've included screenshots of the requests with 429 errors (The ones without errors aren't logged). The first screenshot is at a rate of 6/min, second at 30/min, last one is at 60/min. 
 
The endpoint supposedly has a rate limit of 200 reqs/min according to https://wiki.vg/Mojang_API