Checked it right now, and no, it sets Block fuel correctly, see here an example from a flight plan from LSZH to KLAX:
icao_airline UAE
flight_number 123
route VEBI1T VEBIT T51 LASUN T14 LUMEL T10 TORPA DCT REKLA DCT RLP UL613 SOVAT L613 TLA DCT AKIVO DCT ATSIX DCT 62N020W 63N030W 63N040W 63N050W DCT LIBOR N998A GRIBS DCT 60N071W DCT LENUT DCT GOSEP DCT 55N090W 50N100W DCT FONIA DCT MLS DCT 42N110W DCT FFU DCT EEVUN Q73 HAKMN ANJLL4
passengers (370/370)
airplane B77W
originICAO LSZH
Runway 16
destinationICAO KLAX
est_time_enroute 669.516667
sched_time_enroute 707.000000
sched_out Sat Jul 20 00:20:00 2024
sched_off Sat Jul 20 00:40:00 2024
plan_ramp 101537
units kgs
OEW 168591
ZFW 208870
FSDT_GSX_SIMBRIEF_FUEL = 101537.0
PMDG_Handler setting FUEL Planned 101537 rounded up to 101700
So, because of the customary rounding explained in the manual ( +100 rounded to the next 100th ), block fuel 101537.0 got rounded up to 101700, and that's what I see being inserted in the CDU.