Plasma high CPU consumption for several minutes after drop bucket with many empty indexes

Repro steps:

1. Create hundreds of indexes on an empty bucket with deferred build. (Note: I never issued the build commend, just the create commands with deferred builds. Also, I was trying to create 3,000 empty indexes using cbindex but was not monitoring it, and at some point before ~1,700 indexes the create calls started returning errors. Unfortunately I did not capture those as I'm used to such attempts on my laptop eventually starting to fail, probably due to too high a demand for resources, and don't expect them to be due to a bug.)
2. Drop the bucket and start a rebalance of all nodes immediately. (Rebalance command: curl -u Administrator:asdasd -X POST "http://localhost:9000/controller/rebalance" -d "knownNodes=n_0%40127.0.0.1%2Cn_1%40127.0.0.1%2Cn_2%40127.0.0.1%2Cn_3%40127.0.0.1")
3. Rebalance succeeds. (If it fails stuck in PrepareTopology change, it might be repro of MB-45919, which is what I was trying to reproduce at the time but have not been able to so far.)
4. plasma consumes lots of CPU for several minutes afterwards. Profile (attached) indicates this is doing lots of work under swapperWorker.

I will attach the profile I captured:

1. 100-second CPU sample: pprof.indexer.samples.cpu.001.pb.gz
2. heap mem profile: pprof.indexer.alloc_objects.alloc_space.inuse_objects.inuse_space.001.pb.gz
3. allocs mem profile: pprof.indexer.alloc_objects.alloc_space.inuse_objects.inuse_space.002.pb.gz

Will also attach logs.