The Standard MIDI File specification allows you to store MIDI clock messages in the F7 "escape" or "continuation" form of the sysex event. To check if your MIDI file player will actually send MIDI clocks that are stored in a MIDI file like this, you can try playing the attached MIDI file that contains four 4/4 measures of MIDI clocks at 95 beats per minute.
[
UPDATE 2021-03-23: I created a
Clock MIDI file generator that is easier than the manual methods described below.]
If this works, then the next step is to explore if there's a way you can make a MIDI file containing MIDI clocks at the right tempos for your tracks. For example, you can try editing the example MIDI file in whatever MIDI file editor you normally use. Maybe you can copy and paste the measures to whatever length you want, modify the starting tempo, and insert any other tempo changes needed.
(If editing the example MIDI file doesn't work, it might take more technical work to generate a MIDI file. For example, to make the attached MIDI file I used the MIDI sequencer software
Sekaiju to create the first event and saved it as a
MIDICSV file, then used spreadsheet software to help me generate the other events and pasted them into the MIDICSV file. I can explain further, and/or maybe someone else here can come up with alternative ideas to generate a MIDI file.)