I have used mplabx for pbp3 in the past and find
1. code folding does not work
2. ram usage is always 0
3. it won't complie with dt-ints18 included
tried again this morning
"C:\PBP3\pbpx.exe" -ampasmx -k# -os -p18f45k20 C:/Users/rc/Documents/PBP3/tft/tft.X/tft.pbp
Error[116] C:\USERS\RC\DOCUMENTS\PBP3\TFT\TFT.X\TFT.ASM 2456 : Address label duplicated or different in second pass (Z00183)
Error[116] C:\USERS\RC\DOCUMENTS\PBP3\TFT\TFT.X\TFT.ASM 2519 : Address label duplicated or different in second pass (Z00184)
Error[116] C:\USERS\RC\DOCUMENTS\PBP3\TFT\TFT.X\TFT.ASM 2572 : Address label duplicated or different in second pass (Z00185)
Error[116] C:\USERS\RC\DOCUMENTS\PBP3\TFT\TFT.X\TFT.ASM 2603 : Address label duplicated or different in second pass (Z00186)
a click on the error shows this section of the asm file

Code:
ifdef OSCFIF  ;----{ Osc Fail  Interrupt Flag }-----------[PIR2, OSCFIF]---
      INT_Source  PIR2,OSCFIF, PIE2,OSCFIE, IPR2,OSCFIP
  endif

 ENDASM?

; C:\PBP3\DT_INTS-18.BAS    00313 Z00183 asm
Z00183
 ASM?
; -- Added for ver. 3.2 --
  ifdef SPPIF   ;----{ Streaming Parallel Port Read/Write }--[PIR1, SPPIF]---
      INT_Source  PIR1,SPPIF, PIE1,SPPIE, IPR1,SPPIP
  endif
  ifdef BCL1IF  ;----{ Bus 1 Collision }--------------------[PIR2, BCL1IF]---
4. worst of all you can't comment/uncomment a block of code

I don't think its worth the effort