A few usefull tips on Google Cloud:
I use PuTTY to connect to google cloud or any other VM. Easy to use once you get familiar with it. You can use the same SSH key across multiple instances or beef up the security and create individual keys for each instance and even add another layer of security by applying password on the SSH key.
During creation of a VM click on Management, security, disks, networking, sole tenancy and chose security tab and scroll down to paste the private key you generate in PuTTYgen.
The most powerfull instance ive seen so far is the N2.
When creating a VM click the general purpose tab under machine family and chose N2 series (cascade lake 2.7 ghz). As machine type select custom witch enables you to chose vCPU(thread) count and memory size. LLR tasks require very little memory, so a 2 thread 1 gig VM will be quite productive.
Several 2 thread VM's will be less likely to suffer a shutdown in preemptive mode than say one 16 thread instance.
Creating preemptive VM click Management, security, disks, networking, sole tenancy and chose the management tab and scroll down to Preemptibility and select on
This will reduce price to about a third and your VM will shut down after max 24 hours depending on the load on the datacenter you have chosen. Keep in mind that preemptive instances can be shut down any time and sometimes even after 15 minutes (!) The key is to create a bunch of small VM's spread across different datacenters, and keep an eye on them a couple times a day to restart those that where shut down. Download Cloud Console on your phone if you away for a couple of days. Also be aware that price differs across datacenters.