I don't understand the question, likely because I'm not a programmer. Do you mean handle types it represents, or does it show handles from sub-processes? I've found the content to be the same as I get from handle.exe from Russinovich. So using handle -s to get a summary, my system shows this - I would think all would be represented in Procexp:

C:\WINDOWS\system32>handle -s

Nthandle v4.21 - Handle viewer Copyright (C) 1997-2018 Mark Russinovich Sysinternals - www.sysinternals.com

Handle type summary: ALPC Port : 1437 Composition : 19 CoreMessaging : 10 Desktop : 16 Directory : 100 DxgkSharedResource: 2 DxgkSharedSyncObject: 1 EtwConsumer : 1 EtwRegistration : 1012 Event : 3591 File : 889 FilterCommunicationPort: 8 FilterConnectionPort: 9 IoCompletion : 1429 IoCompletionReserve: 63 IRTimer : 123 Job : 229 Key : 808 Mutant : 61 Partition : 3 PcwObject : 4 Process : 2540 RawInputManager : 63 Section : 1705 Semaphore : 1512 Session : 56 SymbolicLink : 369 Thread : 734 Timer : 81 TmRm : 26 TmTm : 13 Token : 979 TpWorkerFactory : 61 WaitCompletionPacket: 1846 WindowStation : 22 Total handles: 19822