Custom termcap entries and installworld

[Stephen Hurd]

I've now shot myself in the foot at least three times in as many years with 
custom termcap entries... here's the deal:

1) I modify /etc/termcap and customize a termcap entry for some valid reason 
(I need 132x42 or whatever for my Link MC/5)
2) I update /etc/gettytab and /etc/ttys accordingly and happily use my dumb 
terminal on occasion (roughly once per week)
3) I upgrade via sources, being sure to run mergemaster and friends.
4) My terminal stops working.

I have now shot myself in the foot and need to recreate the termcap entry 
(which, silly me, I didn't back up)
Now, intellectually, I *know* that termcap is really stored in 
/usr/share/misc, and that mergemaster doesn't/can't touch those files since 
they're not configuration files... but every single time I run installworld, 
I need to take a manual step to keep things working the way they were 
before.  This is a POLA breaker but I've just ignored it every time it 
happened until now.  This time I opened a PR 
(http://www.freebsd.org/cgi/query-pr.cgi?pr=bin/97407) wishing for 
mergemaster support which, of course, isn't the Right Thing.

So, I suppose my questions are these:
1) How do people cope with custom termcap entries?
2) Is there a *correct* way to cope with custom termcap entries?
3) Is there a good reason to not have /usr/share/misc/termcap be a symlink 
to /etc/termcap rather than the reverse which would allow mergemaster to 
Just Work?  that is... putting it in /etc fixes a problem... does moving it 
create one or more more serious problems?
4) Am I supposed to submit every custom termcap tweak for inclusion in the 
next release so I can keep using my terminals?