If I'm getting this right, your approach would be to start the program at an artificial deficit and apply linear progression until you are at your actual 5 RM. After that, you'd try to introduce a moderate caloric surplus to maintain linear progression. Correct?
The problem I might foresee with this is that maintaining linear progression on a strength-based program like this is something that would be typical for a novice. At 2.5 years of training, assuming your programming prior to this was okay, you should no longer be a novice. Let's find out if you do still qualify as one regarding relative strength.
I've entered the data you've provided in the symmetricstrength.com website, which I consider a good resource for estimating your level because it is based on generally accepted strength standards and research. Here's the results:
- Before bulk in August: 56.6 score, novice level.
- After bulk in December: 62 score, intermediate level.
- After cut, now: 58.7 score, novice level.
The bulk managed to put you into intermediate level. After the cut you've dropped back a bit into novice but you're still stronger overall. Now, this isn't the whole story of course. The real question is: had linear progression on your bulk stalled to the point that adding weight to the bar on at least a two-weekly basis didn't work anymore? No longer being capable of linear progression, and no longer being able to fully recuperate between successive workouts without some sort of periodization are signs you'd no longer be a novice.
Because your strength dropped a bit on the cut, you can probably maintain linear progression again for a while. But I think your approach could have some problems:
- By first introducing an artificial deload, you'll also artificially stretch out the linear progression. However, since you're working at submaximal loads for a while you aren't really making any substantial progress. It might be best to start at your actual 5 RM, or very close to it, and try to increase each lift by 2.5 kg every week, or possibly every 2 weeks.
- Because you're close to intermediate level, doing full-body workouts three times per week with increasing loads might not let you fully recover from workout to workout. A true novice, due to lifting weights far from their physical potential, can recover in about 48 hours, max 72. You possible can't, so you'd need periodization.
- If you attempt to maintain linear progression after having reached your actual 5 RM, you will probably need a bigger caloric surplus than the suggested 200-400 kcal. Which would end up undoing your cut, and at the very least take you over 12% body fat.
When I look at it, what is actually happening is that you're attempting to introduce some periodization into your workout. But rather than working up to an actual max effort and then cycling back, you'd try to keep linear progression going. StrongLifts 5x5 is a beginner program, you are starting to move past that stage.
I'd advise you instead to look into intermediate programming. A good intermediate program would have some periodization, so your increases in weight lifted are now on a monthly or even 6-week basis. You could do a short run-up using StrongLifts 5x5 with linear progression until you start missing lifts, but once you hit intermediate stage, it will have mostly exhausted its usefulness for your situation. If you wish to design your own program with the concepts necessary for an intermediate, you might want to check out the book "Practical Programming for Strength Training" by Mark Rippetoe and Andy Baker.