Restarting primary SQL Server instance with log shipping
It has happened in our case wherein we had to restart our secondary server or log shipping monitoring server as some patches were getting applied and we don't have clustering on them. Our log shipping job is configured to take backup at primary server every 15 minutes, copying and restore also at every 15 minutes however there is gap of 5 minutes in between each of them considering network latency. Only impact we had was one of the job which was scheduled during that window got skipped however no impact on log shipping as lsn number caught up itself on the next copy and restore. 

Based on above experience, I don't expect any issue to happen in your log shipping even if you don't  disable any jobs as the backups will not be taken if primary is down , since remaining two jobs are on secondary server.  Log sequence number will catch up on next backup.

I hope this helps.