25 or 28 gp5000 for 19c (19IW-28OW) rim ?

[tireheb]

i just cant decide, its for deep rims, so im trying to follow the 105% rule.
rims have 28mm of outter width (claimed, i still dont have em, elite edge rim wheelset) so using 105% rule, ideal tire WAM should be 26,6
for what i read 28mm gp5000 on 19mm inner width (like these rims) tend to be 28mm exactly (or maybe 0,2 more).
on the other side 25mm gp 5000's are a bit under 26mm (25,7 for TL, but im going clincher version).

so yeah, the 25mm are closer to the 26,6. and im a light rider so ill be putting around 70-75psi, which means they will be on the thinner side of what most people measured i guess.

but it just feels that im going so much thinner than the 28outter width of the rim. maybe its too much and i should just use 28mm?

yeah, i may be overthinking but thats why we are here no? i got no experience with medium thick wheels, i come from c17's.
thanks!

gPS: got most of the info from:
viewtopic.php?f=132&t=174930
and viewtopic.php?f=3&t=157043

[wheelbuilder]

Start with 25's. If you need more comfort, 28's.