I see the change, but why is it necessary?
I don't know. Arguably, it makes no sense to change the tempo to the tempo's current value, but more would need to be done to determine the current tempo than just looking at the prior offset within the MPC.
Pitch Bend is similar. In the following clip, the first MPC causes 2 events and the second MPC causes 3:
!NoteWorthyComposerClip(2.75,Single)
|Instrument|Name:"Flute"|Patch:73|Trans:0|DynVel:10,30,45,60,75,92,108,127|Pos:10
|MPC|Controller:pitch|Style:Absolute|TimeRes:Quarter|SweepRes:32|Pt1:0,16383|Pt2:1,16383|Pt3:0,8192|Pos:6
|Note|Dur:Whole|Pos:0^
|Bar
|MPC|Controller:pitch|Style:Absolute|TimeRes:Quarter|SweepRes:32|Pt1:0,16383|Pt2:1,16352|Pt3:0,8192|Pos:6
|Note|Dur:Whole|Pos:0
!NoteWorthyComposerClip-End
MFile 1 2 192
MTrk
0 Meta Text "By <Name>"
0 Meta Copyright "Copyright \xc2\xa9 2015 <Name>"
0 Meta Copyright "All Rights Reserved"
0 Meta Text "Generated by NoteWorthy Composer"
0 Meta TrkEnd
TrkEnd
MTrk
0 Meta 0x21 00
0 Meta TrkName "Staff"
0 Par ch=1 c=7 v=127
0 Par ch=1 c=10 v=64
0 PrCh ch=1 p=73
0 Pb ch=1 v=16383
0 On ch=1 n=71 v=110
192 Pb ch=1 v=8192
768 Pb ch=1 v=16383
960 Pb ch=1 v=16352
960 Pb ch=1 v=8192
1488 On ch=1 n=71 v=0
1488 Meta TrkEnd
TrkEnd