The review system is best used if you sign in at least three times a day, due to the review intervals. The first reviews happen 4 hours after you do lessons, and if you get those reviews right, the items return 8 hours after that. Most benefit from hitting those early review intervals to aide retention.
If you don´t need the retention boost, it still means that you progress faster. Radicals and kanji have to hit the Guru SRS stage before new things unlock, so if you want to progress at a reasonable clip, you´re much better off with a minimum of three review sessions a day. One of the most common schedules to suggest is something like 08:00, 12:00 and 20:00.
I personally don’t advocate for doing all lessons at once. I find the bloated review queues very tedious, and if you use a script to reorder lessons, you can go max speed (7 day levels) while sticking to about 20 lessons a day.
(If you’re confused that you levelled up in less than 7 days - the first 2 levels are faster than the rest of WK).
@jprspereira breaks down this method more in a post he made:
So in three months, you can definitely be level 10+, but you don’t feel the real pain of rushing until about 6 months in, when Burn reviews happen. So it can be hard to know what lesson speed keeps you within an amount of reviews that is tolerable for you.
Experiment, I’d say. Try how you like it when going fast, and you can always slow down again.