Lager fermentation with Love TS controller

i have a fridge that is being temp controlled by a love TS controller. i set the SR to 50 and have seen temps that go up to 55/57. i tested it out at 46 for a short period and saw temps only go up to 50, but also down to 46.
What should i set the temp up for a lager. should i just leave it at 50, because the overall temp of the fridge will be 50 and the beers temp will not fluctuate as much as the fridge temps? or bring it down to like 48 so it stays just a bit cooler than 50?
what are you guys doing?
thanks

Where do you have your temp probe? If you stick it to the side of the fermentor and insulate it, you should be able to control the temp of the liquid in side. You don't really care about the temp inside the fridge so much as the temp of the fermenting beer. During the most vigorous stage of ferment I bet the fridge temp is much cooler while it is working to get the beer temp down.

Do you have a way to change the fluctuation? Can you change that? I have a digital controller, and I just change it so there is only a 3 degree differential total, not each way.

There are quite a few different settings that can be changed, but i'm not exactly sure what all of them do. here is the list:

PARAMETERS
Description Units Range
SP Set Point Degrees r1 to r2
r0 Differential or Hysteresis Degrees 1 to 20
r1 Lower Value Set Point Degrees -50 to 150°
r2 Higher Value Set Point Degrees -50 to 302°F (-50 to 150°C)
d0 Heating or Cooling Control Option Ht/Co
d2 Time for Defrosting Minutes 0 to 59 min.
d8 Interval Time between Hours 1 to 24 hr.
Defrosting
c0 Min. Stop Time for Load Minutes 0 to 59 min.
c1 Continuous Cycle Time Hours 0 to 24 hr.
P1 Ambient Probe Adjustment Degrees -10 to 10
H5 Parameter Access Code Numeric 0 to 99 (SET AT 00 FROM FACTORY)
t0 Max. Temp. on Display Degrees -50 to 302°F (-50 to 150°C)

r0 is set to 1. so i would have thought that it would only go between 49-51 if set for 50, but that isnt the case. would i have to set r1 to 49 and r2 to 51?
when i actually put the bucket in there to ferment i am going to secure the probe to the pale, for now i'm just testing the controller to make sure it does what i want it to do. even if i had it secured to the bucket, i would think it would fluctuate just as much, unless it is a timing issue. i have a bucket of Moose Drool that i'm going to cold crash next saturday. i can secure the probe to the bucket and see if i get the same results.
in the mean time i'm just wondering if anyone is doing the same thing and if any settings need to be changed.
thanks

You can fill a bucket with water and see how it works with that although it won't replicate the heat generated by fermentation.

Thanks for the tip MachineShopBrewing. i taped the probe to my bucket with insulation and set it to 50F. it is staying at 50 steady. i guess if its just sitting in the fridge the temp fluctuates too much.