No. If something goes wrong with the beta and you need to fix the iPhone you won't be able to without a computer.
The Apple Beta Software Program lets users try out pre-release software. The feedback you provide on quality and usability helps us identify issues, fix them, and make Apple software even better. Please note that since the public beta software has not yet been commercially released by Apple, it may contain errors or inaccuracies and may not function as well as commercially released software. Be sure to back up your iOS device with iTunes and your Mac using Time Machine before installing beta software. Since Apple TV purchases and data are stored in the cloud, there’s no need to back up your Apple TV. Install the beta software only on non-production devices that are not business critical. We strongly recommend installing on a secondary system or device, or on a secondary partition on your Mac.
Apple Beta Software Program
9. No Support and Maintenance; Future Products.
During your participation in the Beta Program or in a particular seed, Apple is not obligated to provide you with any maintenance, technical or other support for the Pre-Release Software.
If, at Apple’s option, such support is provided, it will be provided in addition to your normal warranty coverage for your computer and/or device.
You agree to abide by any support rules and policies that Apple provides to you in order to receive such support.
You acknowledge that Apple has no express or implied obligation to announce or make available a commercial version of the Pre-Release Software to anyone in the future.
Should a commercial version be made available, it may have features or functionality that are different from those found in the Pre-Release Software licensed hereunder.
Yes, the public beta software is Apple confidential information. Don’t install the public beta software on any systems you don't directly control or that you share with others. Don’t blog, post screen shots, tweet, or publicly post information about the public beta software, and don't discuss the public beta software with or demonstrate it to others who are not in the Apple Beta Software Program. If Apple has publicly disclosed technical information about the public beta software, it is no longer considered confidential.
Read our Terms for full details
If you do install it, you are on your own. We cannot help you here with any issues you may be facing with the Beta, and you will have to sort them out on your own.