$20k is pretty impressive that too for this early, I'd say if you want to go for more ESOPs straightaway they can then potentially change certain terms, I've had this issue once and it backfired on me when I was leaving the organisation.
A better way over time, is to stitch certain milestones maybe during your joining agreement and then getting additional allocation after those milestones are hit
As an ex-founder, I believe this goes on to show how confident you are on your performance metrics and founders appreciate that because they feel you're looking more long term.
As an employee the benefit for you is, you can end up accumulating more ESOPs than you would have at the beginning.
To give you an example, while I was running a revenue vertical at a fairly established org, I stitched my year end revenue milestones with a high esop component, I'd negotiated a 45L additional esop component for 80-85% hit, 55L on 95% hit and then a solid 88L if I deliver anything above 110% or so. While I hit the goals, I had left the org early but they were okay with offering this when I negotiated.