PID in linux emulation

[Malcolm Kay]

I am attempting to run a commercial CAD software
suite compiled for Linux on a FreeBSD 4.10 OS. It runs 
as well or perhaps better than on a Linux box until
the PID becomes large. 

The MAX_PID for FreeBSD is 99999 while Linux has a 
limit of 0x8000.

Once the current PID gets high the interaction of 
software components in the suite fails.

Is there anything I can do about this apart from 
changing to an actual Linux OS? 

Can I edit in /usr/include/sys/proc.h and
recompile the system (kernel) for a lower MAX_PID?
Will it work? Will it lead to other complications?
Is this where the kernel compilation obtains its
value?

Can MAX_PID be changed via sysctl?

Is there someway to reset the current PID without
rebooting?

While I find Linux preferable to MS systems I still
find it much less attractive than FreeBSD with respect 
to file systems, documentation and supported 
applications. And I also need to interact many other
FreeBSD machines on the LAN (and also a few Linux boxes).

Any ideas would be appreciated.

Malcolm