Use the average roll
The rules facilitates the use of average for cases like this and let it use the average of a roll. The average of a d4 is 2.5, thus I round it down to 2 rather than up (3), since it feels more balanced for me that way. I only let roll the d4 in cases where it really needs all the help they can have, but those occasion are rare.
Roll less
The difference between Online and a table is that, depending on the platform and skill of the player, is much slower rolling. Server lag, not having the roll in a macro, not having macros, etc. For that I use the rule number 2 in this guide that is resumed in the title: Rule #2: Only Roll When There is Chance of Success, A Chance of Failure, and A Risk or Cost of Failure. That has save me a lot of rolls and a bunch of time.
Roll even less
I do another little trick, I don't let my players roll when the chances of failing are around 15% (a 1,2 or 3 in a dice). This case comes very rarely, it usually comes when a player has expertise in the relevant skill. Why I do this? The odds are low enough and it gives the player with expertise a nice feeling of empowerment. I only do this online, on the table, I don't, since players seems to like the feeling of rolling the dice.
Players' satisfaction
One problem with using average is that they don't have the impact that wanting a 4 and getting a 3 does. However, I found (by personal experience) that this impact usually happens with combat and Bless, where you can calculate quickly what they need for their bless (they get a feeling on the AC of the enemy). However, this happen less for skills unless it is a do or die situations where they need any edge that they can get.
Now, for experience, the flow in online games breaks easily because things outside player control like lag (Internet or server), disconnections, and oddities (like the second roll always lagging). Other issues might be slow computers (I have one player like this), they don't do macros (or they hate them). Thus, my experience told me that they prefer when things keeps flowing without to much hassle, unless the hassle has worth in it.