What type of finish does the customer want on the trim? If it’s eggshell you could look at Mylands. This product is a hybrid and gives an excellent finish and usually in 2 coats. Just sand the paintwork, wipe over with Krud Kutter Gloss Off and apply 2 coats of finish. Mylands recommend their primer first on painted trim, but believe me you don’t need it.
The product seems fairly thin but opacity is good, if you are overcoating a similar colour, and application is a breeze. You may need to watch for runs on the edge of door frames if you get a build up, but thats all.
They also make a gloss which is a little harder to work with as it has a higher oil content and can be sticky on the brush, like Johnstone’s Aqua. It’s not a really high shine but I haven’t had any complaints when I’ve used it.
Mythic is ok, but needs priming. It is also prone to brushmarks under the wrong conditions.