There
have been a few attempts to alter the original Baybayin for modern use.
One of the first attempts to “reform” the Baybayin was in 1620 when Fr.
Francisco Lopez was about to publish the Ilokano Doctrina. Seeing the
"limitations" of Baybayin, he invented a new kudlit in the shape of a
cross. When placed under a consonant, it would cancel the "a".
I
personally don't like it due to it's colonial origins but I do see the
purpose of it. Thanks a surge of Baybayin tattoos, the Spanish kudlit
has made a comeback due it being the most familiar method of of
isolating the consonant. One common Baybayin tattoo is the Tagalog word
for STRONG - LAKAS. Using traditional Baybayin, it would be written
like this:
Using the Spanish kudlit, the tattoo would look like this:

In my work, I use an X instead of a +.