Getting more than 20 events from Maker API

I would like to be able to pull ALL the events from my HE from a specific device. The documentation shows how to retrieve the last 20 events, and another thread --

-- hints that there might be another parameter to ask for more than 20 events.

BUT all I seem to get is the last 20 events. Below is the output from my attempt.

So, should this length parameter actually work? What am I doing wrong? Is there a way to ask for all the events from a specific device?

events url: http://192.168.1.199/apps/api/161/devices/161/events?access_token=c79ad0a8-c5c4-421f-b55a-e6eca857404e&length=30
events response: Temp Garden 161 data length: 20
47.61 °F 2020-04-27T15:35:34+0000
46.60 °F 2020-04-27T14:45:45+0000
45.70 °F 2020-04-27T14:10:54+0000
44.64 °F 2020-04-27T13:31:04+0000
43.72 °F 2020-04-27T13:06:10+0000
42.64 °F 2020-04-27T12:36:18+0000
41.71 °F 2020-04-27T10:51:47+0000
42.61 °F 2020-04-27T08:47:22+0000
43.51 °F 2020-04-27T01:29:19+0000
44.41 °F 2020-04-27T00:24:36+0000
45.38 °F 2020-04-26T23:49:44+0000
46.39 °F 2020-04-26T23:24:51+0000
47.41 °F 2020-04-26T23:04:55+0000
48.46 °F 2020-04-26T22:45:00+0000
49.41 °F 2020-04-26T22:25:04+0000
50.40 °F 2020-04-26T22:00:10+0000
51.46 °F 2020-04-26T21:35:15+0000
52.54 °F 2020-04-26T21:15:19+0000
53.53 °F 2020-04-26T21:00:21+0000
54.47 °F 2020-04-26T20:45:24+0000

Old post, but I am wondering the same thing.. it seems like the hub saves over 200 recent events so the data is there.

It'd be nice if the MakerAPI /events API could take a few optional params.. by default it could do the same thing as today (last 20) but it'd be nice to add some kind of 'limit' param for the total number returned and/or be able to just return values for a specific attribute (ie: &key=contact)

I've been asked about this in my app - it sounds like maybe smartthings could show more here