So, two things:
Managed app config on Chrome on Android is excellent. There's almost nothing you can't do. There's 170 settings that can be tweaked to get the experience you want:

More here: https://chromeenterprise.google/intl/en_uk/policies/
Secondly, have you considered using a Web Clip instead of a web browser?
1. Go to Systems Manager > Apps
2. Click Add App then Android, ensure that Play Store App is selected and then click Next
3. You should see a bunch of apps:

4. Click the little Globe icon, underneath the Blue Triangle
5. These are where you can create your web apps

6. Click the + in the bottom right
7. Give it a title, a URL and decide how you want the app to work: full screen would appear to be what you need to select
8. select an icon, as necessary
9. Click Create
10. Once created, click select app
11. deploy as necessary
12 . It appears as a regular app now, which means...

13 You can now select it as a kiosk app:

No need for third party kiosk web browsers.