For completeness, here's how I spliced them together, although I tried just adding your commands after my search, entirely, and after my search but without the addcoltotals and neither worked.
| loadjob savedsearch="30 Days Ingest By Index"
| eval day_of_week=strftime(_time,"%a"), date=(strftime(_time,"%Y-%m-%d"))
| search day_of_week=Tue
| fields - _time day_of_week
| transpose header_field=date
| rename column AS index
| untable index date size
| eval date=strptime(date."-2024","%d-%b-%Y")
| fieldformat date=strftime(date,"%F")
| sort 0 index date
| streamstats last(size) as previous window=1 global=f current=f by index
| eval relative_size = 100 * size / previous
| fields - previous
| appendpipe
[| eval date=strftime(date, "%F")." change"
| xyseries index date relative_size]
| appendpipe
[| eval date=strftime(date, "%F")
| xyseries index date size]
| fields - date size relative_size
| stats values(*) as * by index
... View more